National Emission Standards for Chromium Emissions From Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks

Federal RegisterJan 25, 1995

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SUMMARY: Pursuant to section 112 of the Clean Air Act as amended in

1990 (the Act), this action promulgates final standards that limit the

discharge of chromium compound air emissions from existing and new hard

chromium electroplating, decorative chromium electroplating, and

chromium anodizing tanks at major and area sources. Chromium compounds

are among the 189 hazardous air pollutants (HAP) listed for regulation

under section 112 of the Act. Hard and decorative chromium

electroplating and chromium anodizing tanks have been identified by the

EPA as significant emitters of chromium compounds to the atmosphere.

The purpose of the final rule is to reduce chromium compound air

emissions from the source categories identified above. All affected

sources must limit emissions to the level of the maximum achievable

control technology (MACT). The EPA is also finalizing Methods 306,

306A, and 306B with these standards.

DATES: Effective Date: January 25, 1995.

Incorporation by Reference. The incorporation by reference of

certain publications in this standard is approved by the Director of

the Office of the Federal Register as of January 25, 1995.

Judicial Review. Under section 307(b)(1) of the Act, judicial

review of national emission standards for hazardous air pollutants

(NESHAP) is available only by filing a petition for review in the U.S.

Court of Appeals for the District of Columbia Circuit within 60 days of

today's publication of this final rule. Under section 307(b)(2) of the

Act, the requirements that are the subject of today's notice may not be

challenged later in civil or criminal proceedings brought by the EPA to

enforce these requirements.

ADDRESSES: Docket. Docket No. A-88-02, containing information

considered by the EPA in developing the promulgated NESHAP for hard and

decorative chromium electroplating and chromium anodizing tanks is

available for public inspection and copying between 8 a.m. and 5:30

p.m., Monday through Friday, except for Federal holidays, at the EPA's

Air and Radiation Docket and Information Center, Room M1500, U. S.

Environmental Protection Agency, 401 M Street, SW., Washington, DC

20460; telephone (202) 260-7548. A reasonable fee may be charged for

copying.

Background Information Document. A background information document

(BID) for the promulgated NESHAP may be obtained from the docket; the

U. S. EPA Library (MD-35), Research Triangle Park, North Carolina

27711, telephone (919) 541-2777; or from National Technical Information

Services, 5285 Port Royal Road, Springfield, Virginia 22161, telephone

(703) 487-4650. Please refer to ``Chromium Emissions from Chromium

Electroplating and Chromic Acid Anodizing Operations--Background

Information for Promulgated Standards'' (EPA-453/R-94-082b). The BID

contains a summary of the public comments made on the proposed

standards and EPA responses to the comments.

FOR FURTHER INFORMATION CONTACT: Mr. Lalit Banker of the Emission

Standards Division (MD-13), U. S. Environmental Protection Agency,

Research Triangle Park, North Carolina 27711; telephone (919) 541-5420.

SUPPLEMENTARY INFORMATION: The information presented in this preamble

is organized as follows:

I. Background

II. Summary

A. Summary of Promulgated Standards

B. Summary of Major Changes Since Proposal

III. Summary of Environmental, Energy, Cost, and Economic Impacts

A. Environmental and Energy Impacts

B. Cost Impacts

C. Economic Impacts

IV. Public Participation

V. Significant Comments and Responses

A. Selection of Source Categories and Pollutants to be Regulated

B. Selection of MACT/GACT Approach

C. Selection of MACT for Hard Chromium Electroplating Tanks

D. Selection of MACT for Decorative Chromium Electroplating and

Chromium Anodizing Tanks

E. Selection of the Format of the Standard

F. Selection of the Emission Limits

G. Selection of Compliance Dates

H. Selection of Monitoring Requirements

I. Selection of Test Methods

J. Selection of Reporting and Recordkeeping Requirements

K. Operating Permit Program

VI. Administrative Requirements

A. Docket

B. Executive Order 12866

C. Paperwork Reduction Act

D. Regulatory Flexibility Act

E. Miscellaneous

I. Background

Section 112(b) of the Act lists 189 HAP and requires the EPA to

establish national emission standards for all major sources and some

area sources of those HAP. Among the listed pollutants are chromium

compounds. On July 16, 1992 (57 FR 31576), the EPA published a list of

major and area sources for which NESHAP are to be promulgated and on

December 3, 1993 (58 FR 83941), the EPA published a schedule for

promulgation of those standards. The hard and decorative chromium

electroplating and chromium anodizing source categories are included in

the list of major and area sources for which the EPA is to establish

national emission standards by November 1994.

This NESHAP was proposed in the Federal Register on December 16,

1993 (58 FR 65768). A public hearing on this rule was conducted on

January 20, 1994. In addition, 62 letters commenting on the proposed

rule were received during the public comment period, and 3 late

comments were received.

II. Summary

A. Summary of Promulgated Standards

The final rule applies to major and area sources performing hard

chromium electroplating, decorative chromium electroplating, and

chromium anodizing. The affected source is each chromium electroplating

or chromium anodizing tank. The emission limitations for each of these

source categories are summarized in Table 1. These emission limitations

apply only during tank operation, including periods of startup and

shutdown. The emission limitation for all new hard chromium

electroplating tanks, and for existing hard chromium electroplating

tanks that are located at large, hard chromium electroplating

facilities is based on the use of a composite mesh-pad system. The

emission limitation for existing hard chromium electroplating tanks

located at small, hard chromium electroplating facilities is based on

the use of a packed-bed scrubber. For all existing and new sources

performing decorative chromium electroplating and all existing and new

sources performing chromium anodizing, the standard is based on the use

of fume suppressants. Even though these technologies formed the bases

for the standards, any technology can be used as long as it is

demonstrated to meet the prescribed emission limitation. All area and

major sources must limit emissions to the level of the maximum

achievable control technology (MACT).

[[Page 4949]]

Table 1.--Standards for Chromium Electroplating and Chromium Anodizing Tanks Based on MACT

--------------------------------------------------------------------------------------------------------------------------------------------------------

Emission limitations

Type of tank ---------------------------------------------------------------------------------------------------------------------------

Small Large

--------------------------------------------------------------------------------------------------------------------------------------------------------

Hard Chromium Plating Tanks

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All existing tanks.......... 0.03 mg/dcsm (1.3 x 10-5 gr/dscf)........................... 0.015 mg/dscm (6.6 x 10-6 gr/dscf)

All new tanks............... 0.015 mg/dcsm (6.6 x 10-6 gr/dscf).......................... 0.015 mg/dscm (6.6 x 10-6 gr/dscf)

--------------------------------------------------------------------------------------------------------------------------------------------------------

Decorative Chromium Plating Tanks Using a Chromic Acid Bath

--------------------------------------------------------------------------------------------------------------------------------------------------------

All new and existing tanks..

(1) 0.01 mg/dscma(4.4 x 10-6

gr/dscf)

--------------------------------------------------------------------------------------------------------------------------------------------------------

Chromium Anodizing Tanks

--------------------------------------------------------------------------------------------------------------------------------------------------------

All new and existing tanks..

(1) 0.01 mg/dscma(4.4 x 10-6

gr/dscf)

--------------------------------------------------------------------------------------------------------------------------------------------------------

aIn accordance with Sec. 63.342(d)(2), owners or operators using a fume suppressant containing a wetting agent as a control technique can meet an

alternate emission limitation of 45 dynes/cm (3.1 x 10-3 lbf/ft).

Owners and operators of all affected sources are also subject to

work practice standards, which require them to complete an operation

and maintenance (O&M) plan that contains the minimum elements of

Sec. 63.342(f)(3) and Table 2.

Table 2.--Summary of Work Practice Standards

------------------------------------------------------------------------

Control technique Work practice standards Frequency

------------------------------------------------------------------------

Composite mesh-pad 1. Visually inspect device 1. 1/quarter.

(CMP) system. to ensure there is proper

drainage, no chromic acid

buildup on the pads, and

no evidence of chemical

attack on the structural

integrity of the device.

2. Visually inspect back 2. 1/quarter.

portion of the mesh pad

closet to the fan to

ensure there is no

breakthrough of chromic

acid mist.

3. Visually inspect 3. 1/quarter.

ductwork from tank or

tanks to the control

device to ensure there

are no leaks.

4. Perform washdown of the 4. Per manufacturer.

composite mesh-pads in

accordance with

manufacturers

recommendations.

Packed-bed scrubber 1. Visually inspect device 1. 1/quarter.

(PBS). to ensure there is proper

drainage, no chromic acid

buildup on the packed

beds, and no evidence of

chemical attack on the

structural integrity of

the device.

2. Visually inspect back 2. 1/quarter.

portion of the chevron

blade mist eliminator to

ensure that it is dry and

there is no breakthrough

of chromic acid mist.

3. Same as number 3 above. 3. 1/quarter.

4. Add fresh makeup water 4. Whenever makeup is

to the top of the packed added.

beda,b.

PBS/CMP system....... 1. Same as for CMP system. 1. 1/quarter.

2. Same as for CMP system. 2. 1/quarter.

3. Same as for CMP system. 3. 1/quarter.

4. Same as for CMP system. 4. Per manufacturer.

Fiber-bed mist 1. Visually inspect fiber- 1. 1/quarter.

eliminatorc. bed unit and prefiltering

device to ensure there is

proper drainage, no

chromic acid buildup in

the units, and no

evidence of chemical

attack on the structural

integrity of the devices.

2. Visually inspect 2. 1/quarter.

ductwork from tank or

tanks to the control

device to ensure there

are no leaks.

3. Perform washdown of 3. Per manufacturer.

fiber elements in

accordance with

manufacturers

recommendations.

Air pollution control To be proposed by the To be proposed by the

device (APCD) not source for approval by source for approval

listed in rule. the Administrator. by the

Administrator.

------------------------------------------------------------------------

Monitoring Equipment

------------------------------------------------------------------------

Pitot tube........... Backflush with water, or 1/quarter.

remove from the duct and

rinse with fresh water.

Replace in the duct and

rotate 180 degrees to

ensure that the same zero

reading is obtained.

Check pitot tube ends for

damage. Replace pitot

tube if cracked or

fatigued.

Stalagmometer........ Follow manufacturers

recommendations.

------------------------------------------------------------------------

aIf greater than 50 percent of the scrubber water is drained (e.g., for

maintenance purposes), makeup water may be added to the scrubber

basin.

bFor horizontal-flow scrubbers, top is defined as the section of the

unit directly above the packing media such that the makeup water would

flow perpendicular to the air flow through the packing. For vertical-

flow units, the top is defined as the area downstream of the packing

material such that the makeup water would flow countercurrent to the

air flow through the unit.

cWork practice standards for the control device installed upstream of

the fiber-bed mist eliminator to prevent plugging do not apply as long

as the work practice standards for the fiber-bed unit are followed.

[[Page 4950]]

All existing sources performing hard chromium electroplating and

chromium anodizing must comply with the emission limitations within 2

years of January 25, 1995. All existing sources performing decorative

chromium electroplating must comply with the emission limitations

within 1 year of January 25, 1995. All new and reconstructed sources

must comply immediately upon startup.

Sources must demonstrate initial compliance with the prescribed

emission limitation in accordance with Secs. 63.343(b) and 63.344.

Continuous compliance is demonstrated through the monitoring required

by Sec. 64.343(c), as summarized in Table 3. As indicated in this

table, the type of compliance monitoring performed is based on the type

of control technique used to comply with the emission limitation, not

the type of source being controlled.

Table 3.--Summary of Monitoring Requirements

----------------------------------------------------------------------------------------------------------------

Parameter(s) for compliance Frequency of compliance

Control technique Initial compliance test monitoring monitoring

----------------------------------------------------------------------------------------------------------------

Composite mesh-pad (CMP) Yes...................... Pressure drop across the unit. 1/day.

system.

Packed-bed scrubber (PSB) Yes...................... Velocity pressure at the inlet 1/day.

of the control system and

pressure drop across the unit.

PBS/CMP system........... Yes...................... Pressure drop across the unit. 1/day

Fiber-bed mist eliminator Yes...................... Pressure drop across the fiber- 1/day.

bed mist eliminator and the

pressure drop across the

upstream control device used

to prevent plugging.

Wetting agent-type fume Yes (Unless the criteria Surface tension............... Once every 4 hours.a

suppressant. of Sec. 63.343(b)(2) are

met).

Foam blankets............ Yes...................... Foam thickness................ Once per hour.a

Air pollution control Yes...................... To be proposed by the source N/A.

device (APCD) not listed for approval by Administrator.

in rule.

----------------------------------------------------------------------------------------------------------------

aFrequency can be decreased according to Sec. 63.343 (c)(5)(ii) and (c)(6)(ii) of subpart N.

Owners or operators of affected sources are required to keep the

records required by Sec. 63.346 to document compliance with these

standards. Records include those associated with the work practice

standards, performance test results, compliance monitoring data,

duration of exceedances, and records to support a Federally-enforceable

limit on facility size. Reports must also be periodically submitted.

Table 4 summarizes the reports to be submitted and the reporting

timeframes.

Table 4.--Summary of Reporting Requirements

------------------------------------------------------------------------

Section in Subpart N Description Timeframe for submittal

------------------------------------------------------------------------

Sec. 63.345(b)....... Notification of Depends on when source

construction or was constructed--see

reconstruction. Sec. 63.345(b)(5).

Sec. 63.347(c)(1).... Initial notification.... 180 days after the

effective date.

Sec. 63.347(c)(2).... --Notification of when --Within 30 days of

construction commenced. commencement for

sources built after

effective date, or

with notification

required by Sec.

63.345(b) if built

prior to effective

date.

--Notification of actual --Within 30 days of

startup. startup.

Sec. 63.347(d)....... Notification of At least 60 days prior

performance test. to test.

Sec. 63.347(e)....... Notification of Within 90 days of

compliance status. performance test (if a

test is conducted) or

within 30 days of

compliance date.

Sec. 63.347(f)....... Notification of Within 90 days of

performance test performance test.

results.

Sec. 63.347(g)....... Compliance status 2 times/yr, or 4 times/

reports for major yr if exceedances

sources. occur or if requested

by Administrator.

Sec. 63.347(h)....... Compliance status Complete once/yr and

reports for area maintain on site, or 2

sources. times/yr if

exceedances occur or

if requested by

Administrator.

Sec. 63.347(i)....... --Initial notification --Within 180 days of

for users of TVC baths. effective date.

--Notification of --Within 30 days of

compliance status for compliance date.

users of TVC baths.

--Notification of --Within 30 days of

process change. process change.

------------------------------------------------------------------------

B. Summary of Major Changes Since Proposal

In response to public comments received and additional analyses

performed by the EPA, the following changes have been made to the final

rule since proposal:

1. The emission limits associated with the control technologies

that form the bases for the standards have been revised. The emission

limit based on the use of a composite mesh-pad system is 0.015

milligrams of total chromium per dry standard cubic meter (mg/dscm) of

exhaust air. The emission limit based on the use of a fume suppressant

is 0.01 mg/dscm. The emission limit based on the use of a packed-bed

scrubber is unchanged (0.03 mg/dscm).

[[Page 4951]]

Table 3.--Summary of Monitoring Requirements

----------------------------------------------------------------------------------------------------------------

Parameter(s) for compliance Frequency of compliance

Control technique Initial compliance test monitoring monitoring

----------------------------------------------------------------------------------------------------------------

Composite mesh-pad (CMP) Yes...................... Pressure drop across the unit 1/day.

system.

Packed-bed scrubber (PBS) Yes...................... Velocity pressure at the 1/day.

inlet of the control system

and pressure drop across the

unit.

PBS/CMP system........... Yes...................... Pressure drop across the unit 1/day.

Fiber-bed mist eliminator Yes...................... Pressure drop across the 1/day.

fiber-bed mist eliminator

and the pressure drop across

the upstream control device

used to prevent plugging.

Wetting agent-type fume Yes (Unless the criteria Surface tension.............. Once every 4 hours.a

suppressant. of Sec. 63.343(b)(2) are

met).

Foam blankets............ Yes...................... Foam thickness............... Once per hour.a

Air pollution control Yes...................... To be proposed by the source N/A

device (APCD) not listed for approval by

in rule. Administrator.

----------------------------------------------------------------------------------------------------------------

aFrequency can be decreased according to Sec. 63.343 (c)(5)(ii) and (c)(6)(ii) of subpart N.

Table 4.--Summary of Reporting Requirements

------------------------------------------------------------------------

Section in subpart

N Description Timeframe for submittal

------------------------------------------------------------------------

Sec. 63.345(b).... Notification of Depends on when source was

construction or constructed--see Sec.

reconstruction. 63.345(b)(5).

Sec. 63.347(c)(1). Initial notification... 180 days after the

effective date.

Sec. 63.347(c)(2). --Notification of when --Within 30 days of

construction commenced. commencement for sources

built after effective

date, or with notification

required by Sec. 63.345(b)

if built prior to

effective date.

--Notification of --Within 30 days of

actual startup. startup.

Sec. 63.347(d).... Notification of At least 60 days prior to

performance test. test.

Sec. 63.347(e).... Notification of Within 90 days of

compliance status. performance test (if a

test is conducted) or

within 30 days of

compliance date.

Sec. 63.347(f).... Notification of Within 90 days of

performance test performance test.

results.

Sec. 63.347(g).... Compliance status 2 times/yr, or 4 times/yr

reports for major if exceedances occur or if

sources. requested by

Administrator.

Sec. 63.347(h).... Compliance status Complete once/yr and

reports for area maintain on site, or 2

sources. times/yr if exceedances

occur or if requested by

Administrator.

Sec. 63.347(i).... --Initial notification --Within 180 days of

for users of TVC baths. effective date.

--Notification of --Within 30 days of

compliance status for compliance date.

users of TVC baths.

--Notification of --Within 30 days of process

process change. change.

------------------------------------------------------------------------

2. Owners or operators of decorative chromium electroplating tanks

using a trivalent chromium process that incorporates a wetting agent

are required only to submit the notifications required by

Sec. 63.347(i) with subsequent notifications required if the process is

changed or replaced.

3. Existing sources performing hard chromium electroplating and

chromium anodizing must comply with the standard within 2 years after

January 25, 1995. Existing sources performing decorative chromium

electroplating must comply with the standard within 1 year after

January 25, 1995.

4. The monitoring, reporting, and recordkeeping requirements for

affected sources have been reduced to the extent possible while still

allowing the EPA to determine the compliance status on a continuous

basis. Special consideration has been given to area sources.

5. Table 1 of subpart N clarifies which sections of the General

Provisions apply to sources subject to subpart N and which sections do

not.

The rationale for the above changes is discussed in detail in

section V of this preamble, which summarizes the major comments

received on the proposed rule and the EPA's response to these comments.

This section also discusses major comments that were received but that

did not result in changes to the final rule.

III. Summary of Environmental, Energy, Cost, and Economic Impacts

A. Environmental and Energy Impacts

The environmental and energy impacts for the sources covered by

this rulemaking are unchanged from proposal because the bases of the

MACT standards have not changed.

B. Cost Impacts

The annualized cost of control for the sources covered by this

rulemaking remain unchanged from proposal because the bases of the MACT

standards have not changed.

The monitoring, reporting, and recordkeeping burden in the final

rule has decreased from the proposed requirements. Likewise, the costs

of monitoring, reporting, and recordkeeping have also decreased. The

on-going, annual cost of the final monitoring, reporting, and

recordkeeping is approximately 160,000 hours for hard chromium

electroplaters, 29,000 hours for decorative chromium electroplaters

using a trivalent chromium plating process, 260,000 hours for other

decorative chromium electroplaters, and 70,000 hours for chromium

anodizers. Nationwide annual costs for these source categories are $3.5

million for hard chromium electroplaters, $640,000 for decorative

chromium electroplaters using a trivalent chromium plating process,

$5.8 million for other decorative chromium electroplaters, and $1.6

million for chromium anodizers. These numbers [[Page 4952]] are reduced

from the nationwide annual costs associated with monitoring, reporting,

and recordkeeping in the proposed rule of $8.6 million for hard

chromium electroplaters, $1.6 million for decorative chromium

electroplaters using a trivalent chromium plating process, $14 million

for other decorative chromium electroplaters, and $3.8 million for

chromium anodizers.

C. Economic Impacts

The economic impacts for the sources covered by this rulemaking are

unchanged from proposal because the basis of the MACT standards have

not changed.

IV. Public Participation

Prior to proposal of the chromium electroplating and anodizing

rule, meetings of the National Air Pollution Control Techniques

Advisory Committee (NAPCTAC) were held on January 30 and November 19,

1991. These meetings were open to the public, and each attendee was

given an opportunity to comment on the draft rule.

The proposed rule was published in the Federal Register on December

16, 1993 (58 FR 65768). The preamble to the proposal discussed the

availability of the proposal BID (Chromium Electroplating NESHAP--

Background Information for Proposed Standards (Volume I: EPA-453/R-93-

030a and Volume II: EPA-453/R-93-030b)), which describes in detail the

regulatory alternatives considered and the impacts associated with

those alternatives. Public comments were solicited at the time of

proposal, and copies of the proposal BID were made available to

interested parties.

The public comment period officially ended on March 14, 1994. A

public hearing was held on January 20, 1994. In addition, 62 comment

letters were received during the public comment period; 3 late comments

were also received. The comments were carefully considered, and where

determined to be appropriate by the Administrator, changes were made in

the final rule.

V. Significant Comments and Responses

Comments on the proposed rule were received from industry,

environmental groups, and State and local regulatory agencies. A

detailed discussion of these comments and responses can be found in the

promulgation BID (see ADDRESSES section). The summary of comments and

responses in the promulgation BID serves as the basis for the revisions

that have been made to the rule between proposal and promulgation.

A. Selection of Source Categories and Pollutants To Be Regulated

Six commenters said that maximum cumulative potential rectifier

capacity was an inappropriate parameter for determining facility size.

Sources may have excess rectifier capacity to handle atypical

applications, for safety purposes, or for other reasons, but may

routinely operate at a significantly lower rectifier output. Several

commenters urged the EPA to consider alternatives to the maximum

potential rectifier capacity specified, such as actual annual ampere-

hour usage, raising the maximum potential ampere-hour limit for small

sources to 100 million amp-hr/yr, allowing sources to multiply the

maximum potential rectifier capacity by 0.75 to account for oversizing,

or allowing sources to accept Federally-enforceable limits on their

rectifier capacity that would allow them to be categorized as ``small''

facilities.

Although the cutoff between small and large hard chromium

electroplating facilities has not been changed, the EPA has included

two provisions in the final rule to allow sources to use actual

rectifier capacity or to limit their potential rectifier capacity. The

first provision is available to facilities whose production records

show that the previous annual, actual rectifier capacity was less than

60 million amp-hr/yr. Under this provision, hard chromium

electroplating facilities may determine their size by using actual

cumulative rectifier capacity in lieu of the maximum potential capacity

if nonresettable, amp-hr meters are used on affected tanks. The final

rule (Sec. 63.346(b)(12) and Sec. 63.347(c)(1)(vi)) requires that

records of amp-hr usage be kept.

The final rule also allows all sources performing hard chromium

electroplating to establish Federally-enforceable limits on their

rectifier capacity to allow facilities to comply with the standards for

small, hard chromium electroplating tanks, even if those facilities

have potential rectifier capacities that exceed the 60 million amp-hr/

yr cutoff. A Federally-enforceable limit is obtained through the title

V permit that is required by Sec. 63.340(e) of the final rule. Records

are required in accordance with Sec. 63.346(b)(12) and

Sec. 63.347(c)(1)(viii) to document that the Federally-enforceable

limit is being maintained.

The final rule has also been clarified to state that only the

rectifiers associated with hard chromium electroplating should be used

to determine maximum cumulative potential rectifier capacity.

Comments were received regarding other processes conducted by this

source category that were not identified in the process description.

One commenter pointed out a distinction among decorative chromium

electroplating processes: Black chromium and white chromium. The

commenter stated that black chromium electroplating is more like hard

chromium electroplating in terms of process parameters, and the

commenter recommended that black chromium electroplating be subject to

the same requirements as hard chromium electroplating processes. Other

commenters noted that the proposed rule did not cover a hard chromium

electroplating method that uses lower amperage and a longer

electroplating time (less amperage per square foot than decorative

electroplating process) such that emissions are lower.

In the final rule, the definitions of hard chromium electroplating,

decorative chromium electroplating, and chromium anodizing have been

expanded, and are now expressed in terms of process parameters as well

as by function. Regardless of what name a facility has assigned to its

process, for the purposes of the regulation, the process will be

regulated according to its function, bath operating parameters, and

desired plating characteristics. Therefore, black decorative chromium

electroplaters would likely be subject to the standards for hard

chromium electroplaters based on plating characteristics. The EPA will

provide States with additional guidance on these types of applicability

issues in the enabling document.

The commenters that use a low-amperage electroplating process were

concerned that such a process would not be allowed by the rule, even

though emissions from this process are low. Although the process does

differ from other hard chromium electroplating processes in that a

lower amperage is used, the rule does not preclude the use of this

process or any other technique to meet the applicable emission

limitation. The rule does require that the technique be demonstrated

through performance testing conducted in accordance with the test

methods and procedures identified in the final rule, and that

compliance monitoring be conducted to determine continuous compliance.

B. Selection of MACT/GACT Approach

Ten commenters questioned the Agency's decision to regulate area

sources with MACT. A number of these commenters disagreed that the

chromium compound toxicity data alone was justification for regulating

[[Page 4953]] area sources as stringently as major sources. Other

commenters stated that the costs to area sources regulated with MACT

was unduly burdensome, particularly if those sources would be subject

to title V. Two commenters suggested that the EPA apply GACT standards

to small facilities to allow the Agency to focus its resources on

facilities posing the greatest impact, or establish a threshold below

which sources would be subject to GACT. Another commenter questioned

the EPA's decision to apply MACT to area sources on the grounds that

the Act does not intend a residual risk analysis for area sources. This

commenter noted that it was important to have separate standards for

area sources even if GACT was as stringent as MACT to preserve the

intent of section 112(d).

In determining whether to apply MACT or GACT to the area sources in

this source category, the EPA considered the toxicity of chromium

compounds emitted from such sources and the availability of controls.

The EPA has concluded that MACT should be applied to all area sources

in all source categories. The basis for this decision is the toxicity

of chromium compounds. The potency of hexavalent chromium, which is

categorized as a Group A carcinogen, is well documented, and at least

three epidemiological studies have shown a strong association between

lung cancer and occupational exposures to mixtures of trivalent and

hexavalent chromium. Therefore, the Agency has concluded that all

chromium compounds emitted to the air should be considered toxic until

adequate data are available to determine otherwise.

In selecting MACT over GACT for all area sources, the EPA also

evaluated the availability of control technologies and the cost of

compliance for area sources. The control technologies that form the

bases for MACT are widely available.

Although Sec. 112(d)(5) of the Act does allow an alternative

standard for area sources, the EPA interprets this paragraph as

authorizing the Administrator to establish GACT standard for area

sources when the imposition of MACT is determined to be unreasonable.

For the source categories subject to subpart N, the Agency considers it

reasonable to apply MACT to area sources.

C. Selection of MACT for Hard Chromium Electroplating Tanks

1. Selection of the MACT Floor

Four commenters suggested that the MACT floor for new hard chromium

electroplating tanks should be based on the use of a fiber-bed mist

eliminator (FBME) because this is the best technology in use.

The EPA has gathered additional information since proposal in

response to public comments received. Based on this information, a

total of five facilities are known to be using FBME to control chromium

emissions from affected hard chromium electroplating and chromium

anodizing tanks. These five facilities represent different sizes of

hard chromium electroplating and chromium anodizing operations.

Emission test data were obtained from four of the five facilities

using FBME (see Item No. IV-B-01 of Docket A-88-02). The emission test

data available from one facility were incomplete and could not be used

to assess the performance of fiber-bed units. The test results from the

other facilities were adequate to evaluate the performance of FBME.

However, after a thorough evaluation, it was determined that the

limited data are not sufficient to establish an emission limit which

must be met on a continuous long-term basis. In one case, the data were

inadequate because only a single traverse was made when two should have

been performed. In the other cases, the quantity of emissions captured

during sampling was too small to meet Agency guidelines on minimum

quantification levels. These data, therefore, must be treated as

qualitative rather than quantitative results and may not be used to

establish achievable emission limits. Based on this qualitative

assessment, it appears that FBME offer excellent control potential.

In evaluating control technologies, the Agency also must consider

the sustainability of any performance level. The EPA is concerned with

the long-term performance of these systems because of the tendency of

the fiber beds to plug. In other contexts, most vendors of FBME systems

do not recommend their use as primary pollution control systems.

Rather, they recommend that coarse prefiltering be provided upstream of

the fiber beds to prevent plugging. The prefiltering devices range from

a series of mesh pads to a complete packed-bed scrubber unit. At

present, there are no long-term data available to assess any actual

deterioration or operational problems associated with FBME. Fiber-bed

mist eliminators to control chromium electroplating and anodizing tanks

have only recently been installed as a result of local air district

requirements; therefore, it is unlikely that any long-term data are

available.

Because of the uncertainties in both the measured FBME performance

data and the potential long-term variability of the system performance,

the Administrator cannot at this time determine that a more stringent

emission limit could be achieved based on the application of FBME

technology for new hard chromium plating or chromium anodizing

operations. Therefore, the final MACT performance level of new hard

chromium electroplating and chromium anodizing tanks is unchanged from

the proposal. However, the limited data do suggest that FBME systems

can achieve the emission limits established for composite mesh-pad

systems and fume suppressants. Because this standard is a performance

standard, the use of a specific technology is not mandatory; therefore,

any system that meets or exceeds the required performance level may be

used.

In order to facilitate the use of FBME to achieve compliance with

the standard, monitoring provisions have been included in the final

rule for use with FBME. (See discussion in section V.H.) The test

methods in the proposed rule are suitable for demonstrating compliance

with the standard regardless of the control technology employed.

2. Regulatory Alternatives Considered

Eight commenters suggested that the EPA was too limiting in the

regulatory alternatives for hard chromium electroplating operations.

These commenters believed that the EPA should allow sources in this

subcategory to use fume suppressants to comply with the standard,

instead of locking sources into a control technology, such as packed-

bed scrubbers. Four of the commenters also proposed that the EPA allow

new and existing hard chromium electroplating operations the option of

meeting the same surface tension limit allowed for decorative chromium

electroplating operations that use a wetting agent-type fume

suppressant.

The EPA has selected an emission limit format to provide sources

with the flexibility to choose the emission control strategy best

suited to their facility. The regulation only requires that any

strategy selected meet the emission limits set out in the rule. As

such, hard chromium electroplating sources can use fume suppressants to

achieve compliance with the standard, as long as initial compliance

testing demonstrates that the emission limit stipulated in the standard

is being achieved. As discussed later in this preamble, however, on-

going compliance monitoring is control-technique specific. As such, the

owner or operator of any source that uses a fume suppressant to comply

with an emission limitation shall monitor surface tension or foam

blanket [[Page 4954]] thickness, as appropriate, to demonstrate

continuous compliance.

3. Selection of MACT

Several commenters remarked that the standard for existing hard

chromium electroplaters is inappropriate. Nine commenters stated that

the standard was too stringent for large, hard chromium electroplaters;

small, hard chromium electroplaters; or both. The arguments against

regulating existing hard chromium electroplaters as stringently as that

proposed were primarily that the costs associated with the standard

were unduly burdensome and did not justify the resulting environmental

benefit, and the emission concentration limits specified in the

proposed rule were not consistently achievable using the control

devices upon which the standards are based.

Five commenters, on the other hand, indicated that the standard for

small, hard chromium electroplaters was too lenient. The arguments

presented by the commenters who supported a more stringent standard for

small, hard chromium electroplaters were that the residual risk

associated with emissions from these sources warranted more stringent

controls, the Agency's interpretation of the MACT floor was flawed

(i.e.; should be based on a straight average, not a median); and the

control efficiency for packed-bed scrubbers is overstated, as are the

cost impacts for a standard based on the use of composite mesh-pad

systems.

In setting an emission standard, the Act directs the Administrator

to take into account costs, nonair quality health and environmental

impacts, and energy requirements. To fulfill this requirement for

existing hard chromium electroplating sources, the EPA evaluated the

cost, impact, and benefit of a standard based on the use of a packed-

bed scrubber as well as a standard based on the use of a composite

mesh-pad system. The Agency's estimate of the incremental cost

effectiveness of requiring all sources to meet a standard based on

composite mesh-pad systems compared to one based on packed-bed

scrubbers is approximately $3.7 million per Megagram of chromium

controlled ($/Mg) for large sources and $10.7 million/Mg for small

sources.

Based on the EPA's economic analysis, a standard based on the use

of composite mesh-pad systems by all sources would not cause adverse

economic effects on large sources that currently use packed-bed

scrubbers. Due to economies of scale, the economic impacts on larger

facilities are consistently less than those on small facilities. As a

result, larger facilities will have a greater ability to pass on

control costs. Although these costs may seem high, the EPA believes the

toxicity of chromium justifies these costs. In consideration of the

potential adverse impacts to small sources, the final rule requires a

less stringent standard for small sources than large sources, which is

based on the use of packed-bed scrubbers rather than composite mesh-pad

systems. [See Chapter 5 of the New Technology Document (``Technical

Assessment of New Emission Control Technologies Used in the Hard

Chromium Electroplating Industry;'' EPA-453/R-93-031) for a detailed

discussion of EPA's economic analysis for these systems.]

The EPA considers the emission limitation based on the use of

composite mesh-pad systems to be representative of and consistently

achievable with well-maintained units. No data were submitted to

support an alternate emission limitation. (For further discussion of

the emission limitations, see section V.F.)

Regarding the comments that the proposed standard for small, hard

electroplaters was too lenient, the Agency believes that the MACT floor

is properly based on the use of packed-bed scrubbers for this source

category. The EPA promulgated a final rule on June 6, 1994 (57 FR

29196) that presents the Agency's interpretation of section 112(d)(A)

of the Act regarding the basis for the MACT floor. Under this

interpretation, the Agency considers the emission limitations achieved

by the best performing 12 percent of existing sources and arrives at

the MACT floor by selecting the median of the values, rather than a

straight average. This interpretation was followed in establishing the

MACT floor for small, hard chromium electroplaters. The Agency

considers any discussion of the risk remaining from small, hard

chromium electroplaters to be premature at this time.

In accordance with section 112(f) of the Act, if a significant

residual risk from small, hard chromium electroplating operations

regulated by MACT is found, the Agency is required to promulgate

standards to mitigate that risk. The EPA recognizes the potential

hazards of chromium emissions from small sources and has chosen to

regulate area sources with MACT rather than GACT. The EPA also

considers its cost and impact analysis for small, hard chromium

electroplaters to be sound. The EPA estimated retrofit costs based on

information from vendors who supply the equipment to the industry, and

therefore estimates are representative of the control costs incurred by

affected sources. The EPA considers the efficiency assigned to packed-

bed scrubbers for purposes of calculating impacts to be representative

of that achieved by well-maintained and well-operated units controlling

emissions from hard chromium electroplating tanks. As with comments on

the emission limit based on composite mesh-pad systems, no data

supporting alternate emission limits for a standard based on packed-bed

scrubbers were submitted.

D. Selection of MACT for Decorative Chromium Electroplating and

Chromium Anodizing Tanks

1. Regulation of the Trivalent Chromium Plating Process

Eleven commenters disagreed that decorative chromium electroplating

tanks that use a trivalent chromium process should be regulated by the

proposed rule. Many of the commenters felt that the EPA had

insufficient data to conclude that the risk associated with this

process warranted regulation of those sources. Four commenters found

fault with the EPA's supporting data and noted that the level of

hexavalent chromium in a trivalent chromium bath that corresponds to

the EPA's estimate of hexavalent emissions from that bath would far

exceed that level of hexavalent chromium that would destroy the

trivalent bath. Three other commenters stated that use of the trivalent

chromium process should be encouraged by the EPA, because trivalent

processes result in less total chromium in process wastewater and less

sludge generation. One of the commenters suggested regulating trivalent

chromium electroplating processes under GACT to eliminate some of the

burden associated with the reporting, recordkeeping, and monitoring

requirements specified in the proposed rule.

Twelve commenters responded to the EPA's request for comment on

whether the trivalent chromium electroplating process should be

required for new sources. The majority of these commenters did not

think that this should be a requirement because the process was not

technically feasible for the full range of decorative chromium

electroplating operations. Two commenters pointed out inconsistencies

in the EPA's reasoning; the EPA can only require trivalent chromium

baths if it recognizes the difference in toxicity between hexavalent

and trivalent chromium.

The EPA has reconsidered the technical basis for regulating tanks

[[Page 4955]] using the trivalent chromium electroplating process and

the feasibility of requiring such a process for new sources. During

development of the proposed standards, the EPA evaluated the trivalent

chromium electroplating process as a pollution prevention alternative.

Chromic acid is not present in the plating solution in the trivalent

chromium processes, and hexavalent chromium is regarded as a bath

contaminant in these processes. In addition, all of the trivalent

chromium plating solutions with which EPA is familiar contain a wetting

agent as an inherent bath component. That is, the wetting agent is part

of the plating solution purchased from the vendor; it is not added

separately by the end user.

With a trivalent chromium plating process, the potential emissions

of chromium in any form are much lower because the concentration of

total chromium in trivalent chromium baths is approximately four times

lower than the total chromium concentration in chromic acid baths.

Trivalent chromium processes greatly reduce emissions of the most

potent form of chromium (hexavalent), and significantly lower emissions

of chromium in other forms. In addition to reduction of air emissions,

the use of trivalent chromium processes results in lower chromium

concentrations in process wastewaters and, consequently, reduces the

amount of sludge generated. Based on a source test conducted by the

EPA, total chromium emissions from a trivalent chromium bath are

approximately 99 percent less than those from a traditional,

uncontrolled decorative hexavalent chromium bath. Hexavalent chromium

emissions from a trivalent chromium bath were found to be approximately

equivalent to those emitted from a decorative hexavalent chromium bath

controlled by adding a wetting agent.

Although chromium emissions from the trivalent chromium process

were low, the EPA had not anticipated the presence of hexavalent

chromium in emissions from the trivalent electroplating process nor the

level of total chromium emissions. Given that the Act lists all forms

of chromium on the HAP list, the EPA considered the trivalent chromium

electroplating process as a source of chromium emissions as well as an

emission control alternative for the chromic acid electroplating

process. Based on the emission test results, a decorative hexavalent

chromium bath controlled by adding a wetting agent had equivalent

hexavalent chromium emissions and less total chromium emissions than a

trivalent chromium plating bath. (As previously stated, for trivalent

chromium baths, the wetting agent is inherent to the solution; it does

not need to be added by the user.) In addition, the trivalent chromium

process may not be technically feasible for all decorative chromium

electroplating applications. Therefore, the final rule does not require

the use of a trivalent chromium electroplating process for either

existing or new decorative chromium electroplating tanks.

The EPA has decided to regulate sources that use trivalent chromium

baths in the final rule. It is not clear whether the EPA data

accurately reflect emissions from the trivalent chromium electroplating

process, or if the analytical integrity of the data is suspect. In

light of the ambiguity of the air emissions data, and given the other

environmental benefits from the trivalent chromium process, the EPA has

decided to regulate these baths differently from hexavalent chromium

electroplating baths.

The final rule requires users of trivalent chromium baths to submit

an initial notification and a notification of compliance status

certifying that a trivalent chromium bath is being used and identifying

the bath components (specifically, the wetting agent). Subsequent

notifications are required only if the process is changed, or if a new

trivalent chromium process is introduced. Users of trivalent chromium

baths must also keep records of bath chemicals purchased so the EPA can

be assured that the bath contains a wetting agent. These notification

and recordkeeping requirements apply only to those trivalent chromium

baths that incorporate a wetting agent. The EPA has evaluated baths

with this characteristic and found them to have the environmental

benefits discussed above. Although such baths are not known to exist,

the EPA has chosen to regulate trivalent chromium baths that do not

incorporate a wetting agent in the same manner as decorative chromium

baths using a chromic acid solution. The EPA believes that this will

discourage the use of a trivalent chromium bath that does not have a

wetting agent as an inherent bath component.

2. Selection of MACT for Decorative Chromium Electroplating Tanks

Three commenters suggested that the proposed emission limit of

0.003 mg/dscm for decorative chromium electroplaters using hexavalent

chromium baths was too stringent. Two commenters did not think that a

source using either a fume suppressant or a fume suppressant in

conjunction with a packed-bed scrubber could consistently meet a limit

of 0.003 mg/dscm.

In response to the comments received at proposal, the EPA has

reconsidered the basis for the emission limit of 0.003 mg/dscm for

decorative chromium electroplating and chromium anodizing tanks. As

stated in the preamble to the proposed rule, this emission limit was

based on tests of a decorative chromium electroplating tank in which a

combination wetting agent/foam blanket was used to control emissions.

Tests had also been conducted on a decorative chromium electroplating

tank using only a foam blanket for control. The chromium emission data

for all types of fume suppressants ranged from 0.001 to 0.007 mg/dscm,

with the wetting agent/foam blanket data ranging from 0.001 to 0.003

mg/dscm and the foam blanket data ranging from 0.003 to 0.007 mg/dscm.

In evaluating whether the proposed emission limit of 0.003 mg/dscm

should be revised in the final rule, the EPA reassessed the effect the

test methods may have had on the emission data obtained. The analytical

method used for the fume suppressant test was colorimetric

spectroscopy. As more efficient control technologies (such as composite

mesh-pad systems) were developed, a more sensitive analytical method

was needed to measure the lower concentrations of chromium being

emitted. Therefore, the more sensitive ion chromatography method was

used in the later phases of emission testing for these standards

involving add-on control devices.

By using the less sensitive colorimetric analytical method, it is

unclear whether the variation found between the two types of fume

suppressants was due to a performance difference in the fume

suppressants or was an artifact of the analytical method used. The fact

that there is overlap between the foam blanket and wetting agent/foam

blanket data further indicates that this could be the case. (Both were

able to achieve a limit of 0.003 mg/dscm in one instance.) Therefore,

the EPA has concluded that the emission limit in the final rule should

be based on the performance of both foam blankets and wetting agents.

Accordingly, the emission limit selected for decorative chromium

electroplating and chromium anodizing tanks in the final rule is 0.01

mg/dscm. This emission limit was selected by applying a safety factor

to the highest measured data point (0.007 mg/dscm) to account for

variations in sampling and analytical procedures. The selection of this

emission limit is consistent with the methodology used to select

emission limits based on other control [[Page 4956]] techniques, as is

further discussed in section V.F.

3. Selection of MACT Floor/MACT for Chromium Anodizing Tanks

Three commenters questioned the MACT floor established by the EPA

for sources performing chromium anodizing. The commenters stated that

it did not appear that the EPA had sufficient data to perform a MACT

floor analysis for these sources. Commenters stated that chromium

anodizers and decorative chromium electroplaters that cannot use fume

suppressants should be considered separately, and the MACT floor for

such sources should be based on packed-bed scrubbers. Also, according

to six commenters, the standard for chromium anodizing tanks is not

achievable in all situations, especially when an add-on control device

is used in lieu of fume suppressants. One commenter stated that unless

the standard for chromium anodizing tanks controlled with add-on

control devices is set at 0.03 mg/dscm, sources will have to use an

add-on control device followed by a fiber-bed mist eliminator to

achieve the emission limit.

The MACT floor for chromium anodizing sources was based on

information available to the EPA on the source category. Information on

the industry was obtained through survey questionnaires to both

industry representatives and control system vendors, site visit

reports, and available emission data. Although information was not

available from all sources in the category, the EPA believes the

information was sufficient to satisfy the requirements of section

112(d)(3) of the Act. The survey responses, which included some

aerospace facilities, indicated that fume suppressants were the control

technique used predominantly in the industry. Section 112(d)(3) of the

Act prohibits the EPA from establishing a standard that is any less

stringent than the MACT floor for a category or subcategory of sources.

No technical reason was provided by industry, nor is one known to the

EPA, for creating a separate subcategory of sources for which fume

suppressants are not technically feasible. Thus, all new and existing

sources performing chromium anodizing must meet either an emission

limit of 0.01 mg/dscm or maintain the surface tension specified in the

rule. The EPA believes that the revised chromium emission limit of 0.01

mg/dscm for chromium anodizing tanks in the final rule is achievable by

sources using add-on control technology. Alternatively, the EPA

believes that the compliance timeframe for existing sources performing

chromium anodizing in the final rule (2 years) will allow these sources

to further investigate the feasibility of using fume suppressants.

E. Selection of the Format of the Standard

Seven commenters stated that the format of the standard should be

expressed as a process emission rate in milligrams of chromium emitted

per amp-hour of operation (mg/amp-hr), which would be consistent with

California rules, rather than as an emission concentration (mg/dscm).

According to the commenters, concentration-based standards are flawed

because they can be circumvented by dilution, concentration can vary

from system to system, and source test data indicate that outlet

concentrations vary widely for different inlet conditions. Several

commenters also pointed out that emissions should be correlated to

production rates because chromium emissions increase proportionately

with increased current. Two other commenters suggested that the final

rule specify acceptable process emission rates to avoid an equivalency

evaluation.

Based on the Agency's evaluation, the available test data indicate

that a process emission rate format will not ensure consistent

compliance with the control level required by the standard. The

concentration data collected by the EPA for the composite mesh-pad and

packed-bed scrubber systems do not overlap; that is, composite mesh-pad

systems consistently outperform packed-bed scrubbers. The process

emission rate data, on the other hand do overlap; even though composite

mesh-pad systems are a superior technology to packed-bed scrubbers,

both sometimes achieve the same process emission rate. This occurs

because two sources can be using the same control technology and

achieving the same outlet emissions concentration, but the one with the

higher current loading will have a lower process emission rate.

Commenters contend that this is reasonable because the production rate,

as measured in ampere-hours, is related to emissions. However, the

amount of current supplied to the tank is an indicator of the amount of

uncontrolled emissions from the tank, not the controlled emission level

from the tank. Because of the differences in process emission rate-

based and concentration-based standards, and the source-specific nature

of process emission rate standards, the EPA cannot cite an equivalent

process emission rate in the final rule.

Regarding the issue of circumvention of the standard through

dilution of the emission stream, the EPA believes that dilution of the

gas stream can be determined by reviewing test and permit data for a

facility. The outlet air flow rate measured during testing should

approximate the design air flow rate for the control system reported on

the permit application. If the two values differ significantly, then an

inspection of the control system can be made to determine if dilution

air is being introduced. It is also possible for a facility to dilute

the inlet gas stream to the control device by designing a system to

ventilate the electroplating tanks at air flow rates substantially

above those required for adequate ventilation. However, the increased

installation and maintenance costs associated with such a system would

outweigh the costs of complying with the standard without dilution.

Further, Sec. 63.4(b) of the General Provisions expressly prohibits

dilution as a means to comply with an emission limit. Therefore,

concerns of dilution of the air stream were not considered to outweigh

the benefits of a concentration-based format for the standard.

Eight commenters disagreed with the EPA's decision to base the

standard on emissions of total chromium rather than on emissions of

hexavalent chromium. Two commenters suggested allowing sources to

demonstrate compliance by testing for hexavalent chromium in lieu of

total chromium.

The EPA decided to base the standard on total chromium because the

HAP list identifies all chromium compounds, not just hexavalent

chromium compounds. In addition, based on testing conducted by the EPA

for these source categories, the available test data indicate that

hexavalent and total chromium levels in the emission stream were

essentially the same for chromic acid baths (varying within

10 percent in most instances). Because the EPA data base is

mainly comprised of data measured as hexavalent chromium, the final

rule does allow all sources using chromic acid baths to demonstrate

compliance by measuring either hexavalent or total chromium for all

sources.

F. Selection of the Emission Limits

Many commenters stated that the emission limit based on the use of

composite mesh-pad systems should be changed. Three commenters

suggested lowering the emission limit that is based on the use of

composite mesh-pad systems, stating that the EPA did not test the best

systems available, and suggested levels ranging from 0.001 mg/dscm to

0.009 mg/dscm. Other [[Page 4957]] commenters stated that the proposed

limit based on composite mesh-pad systems (0.013 mg/dscm) was too low.

Five commenters stated that the proposed emission limit for packed-bed

scrubbers was also too high, noting that some units tested by the EPA

did not achieve this limit.

The proposed emission limit of 0.013 mg/dscm for large hard

chromium electroplaters was based on tests that the EPA conducted on

actual control devices operating under normal process conditions. Lower

limits than the one selected for large sources were measured from these

devices, but the EPA based the emission limit on the highest measured

data point and believes that this limit is consistently achievable.

Regarding the emission limit based on packed-bed scrubbers, the EPA did

test some packed-bed scrubber systems that were not achieving the level

of 0.03 mg/dscm required by the proposed standard. However, these

devices were not optimized to achieve the higher removal efficiencies.

Specifically, when scrubbers were operated with periodic or continuous

washdown in which fresh water was supplied as makeup to the top of the

bed, a limit of at least 0.03 mg/dscm was achieved. The final rule

includes work practice standards that require the use of fresh water

added to the top of the packed bed whenever makeup additions occur.

Thus, packed-bed scrubbers that are operated in accordance with the

requirements of the rule should be able to achieve a limit of 0.03 mg/

dscm. The EPA does not think it is appropriate to substantially change

the emission limits based on the use of composite mesh-pad systems or

packed-bed scrubbers; the commenters did not provide data that

supported their claim that different emission limits are more

appropriate.

As discussed previously, the emission limit for decorative chromium

electroplating tanks and chromium anodizing tanks has been changed to

0.01 mg/dscm in the final rule by applying a safety factor to the

highest data point (0.007 mg/dscm) in the fume suppressant data base.

Similarly, the emission limit that is based on packed-bed scrubbers is

based on rounding the highest value (0.028 mg/dscm) in the packed-bed

scrubber data base to 0.03 mg/dscm to incorporate a safety factor.

Therefore, in the final rule, the emission limit that is based on the

use of composite mesh-pad systems (0.013 mg/dscm) has been adjusted to

0.015 mg/dscm by applying a safety factor to the highest value (0.013

mg/dscm) in the data base to ensure that the limit is achievable on a

consistent basis.

G. Selection of Compliance Dates

Several commenters stated that the proposed compliance dates for

affected existing sources did not allow sufficient time to achieve

compliance with the proposed rule. The majority of these commenters

suggested compliance timeframes of 2 to 3 years. According to the

commenters, the compliance period specified in the proposed rule did

not allow enough time to inform and educate affected owners and

operators; acquire capital; conduct research and test systems;

identify, purchase, and install control equipment; develop startup,

shutdown, and malfunction plans; train staff; build inventories; and

establish reporting and recordkeeping systems.

The Agency agrees with the commenters that the compliance

timeframes for affected sources should be increased. The EPA recognizes

that some of the facilities within all of the source categories will

have to investigate the technical feasibility of installing control

devices or using other technologies at their facility to meet the

standards. Also, many area sources are not yet aware that a rule is to

be promulgated for their industry, and time is needed for them to be

made aware of the requirements of this rule. Therefore, the EPA has

extended the compliance date to 1 year after the promulgation date for

existing decorative chromium electroplaters and 2 years after the

promulgation date for existing hard chromium electroplaters and

chromium anodizers. The EPA believes that the 1 year timeframe for

decorative chromium electroplaters is sufficient because, based on the

EPA's survey data, 80 percent of existing sources already use fume

suppressants and very few will need to install add-on air pollution

control devices. The EPA thinks that the compliance timeframes in the

final rule will address commenters concerns and still ensure

implementation of controls in a timely fashion. Due to the toxicity of

chromium compounds and the importance of controlling chromium emissions

to protect human health and the environment, the Agency decided against

a compliance time longer than 2 years for any of the source categories

affected.

To accommodate sources that cannot comply with the standard by the

compliance date, Sec. 63.6(i) of the General Provisions and

Sec. 63.343(a)(6) of subpart N allows a source to request a 1-year

compliance extension, which must be submitted 6 months in advance of

the compliance date identified in the regulation. This extension

combined with the compliance timeframes in the proposed rule could

provide a total of 2 years for compliance for decorative chromium

electroplaters and 3 years for compliance for hard chromium

electroplaters and chromium anodizers.

H. Selection of Monitoring Requirements

Section 114(a)(3) of the Act requires enhanced monitoring and

compliance certification of all major stationary sources. The annual

compliance certifications certify whether compliance has been

continuous or intermittent. Enhanced monitoring shall be capable of

detecting deviations from each applicable emission limit or standard

with sufficient representativeness, accuracy, precision, reliability,

frequency, and timeliness to determine if compliance is continuous

during a reporting period. The monitoring in this regulation satisfies

the requirements of enhanced monitoring.

1. Compliance Monitoring for Add-on Air Pollution Control Devices

Eleven comments addressed the suitability of measuring gas velocity

to demonstrate on-going compliance when add-on air pollution control

devices are used to comply with an emission limit. The commenters

stated that measuring gas velocity is very complicated, redundant with

measuring pressure drop, and not indicative of control device

performance. Two commenters pointed out that no suitable testing point

may be accessible, and a permanent measurement device may be fouled by

chromic acid.

Several commenters remarked on the requirement for measuring

chromium concentration in the scrubber water. Four of these commenters

stated that there is no obvious relationship between scrubber water

chromium concentration and scrubber performance. Other commenters

indicated that measurement of chromium concentration in scrubber water

with a hydrometer is not accurate.

In revising the proposed rule, the EPA recognizes that the

measurement of gas velocity could be burdensome and that other control

system parameters could potentially be used to determine on-going

compliance. Therefore, in the final rule, sources using composite mesh-

pad systems are required to monitor pressure drop across the device for

compliance purposes. Based on information gathered by the EPA, pressure

drop is directly related to composite mesh-pad system performance,

measurement of pressure drop is straightforward, and some users of

composite mesh-pad systems are currently monitoring pressure drop. The

[[Page 4958]] EPA believes that this change makes the rule more

flexible for regulated sources, while still ensuring that the EPA has a

mechanism for determining compliance with the emission limits at any

given time.

The final rule requires sources that use a packed-bed scrubber to

meet the emission limit must measure the velocity pressure at the inlet

to the control system as well as the pressure drop across the device.

The relationship between pressure drop and packed-bed scrubber

performance is less reliable than the relationship between pressure

drop and composite mesh-pad system performance because of the lower

pressure drop in packed-bed scrubbers. Therefore, the EPA also requires

sources using packed-bed scrubbers to monitor the velocity pressure at

the inlet to the control device. This requirement will ensure that the

gas velocity through the control system is maintained in accordance

with vendor recommendations and, along with the pressure drop

monitoring, will ensure that the control system is properly operating.

The requirement that sources using packed-bed scrubbers monitor the

chromium concentration in the scrubber water has been eliminated,

because the EPA concluded that monitoring of the velocity pressure at

the control device inlet and the pressure drop across the device was

sufficient to demonstrate compliance with the emission limits when

packed-bed scrubbers are used.

Compliance monitoring requirements for fiber-bed mist eliminators

have been added in the final rule because these devices could likely be

used to meet the emission limitations, and some fiber-bed mist

eliminators are known to be in use. Sources that use a fiber-bed mist

eliminator to meet the emission limit must measure the pressure drop

across the fiber-bed unit, as well as the pressure drop across the

control device upstream of the fiber-bed unit that is in place to

prevent plugging.

As discussed above, several changes have been made to the

monitoring requirements specified in the proposed rule based on the

EPA's review of comments received on the proposed rule and further

investigation of which process parameters relate best to proper

performance of the control systems. The final compliance monitoring

requirements are found in Sec. 63.343(c) of the final rule.

2. Work Practice Standards for Add-on Air Pollution Control Devices

In the proposed rule, Operation and Maintenance (O&M) requirements

for add-on air pollution control devices consisted of adding makeup

water to packed-bed scrubbers, requiring washdown of composite mesh

pads, and various inspections for both types of control devices. The

majority of comments focused on the requirements associated with makeup

water for packed beds and washdown for composite mesh pads. Several

commenters suggested alternatives for the requirements for adding

makeup water to packed-bed scrubbers. The commenters disagreed that

makeup water can or should be added to the top of the scrubber. Others

questioned the need to use fresh water in scrubbers and composite mesh

pads because doing so increased wastewater flows. Other commenters

requested that the final rule define the term ``fresh water.''

In the final rule, the O&M requirements have been replaced with

work practice standards that address O&M practices [Sec. 63.342(f)].

The final rule continues to require sources using packed-bed scrubbers

to meet an emission limit and ensure that all makeup water is fresh and

supplied to the unit at the top of the packed bed. The EPA considers

this requirement essential to meeting the prescribed emission limit.

During source testing conducted by the EPA to establish the performance

level of packed-bed scrubbers, it was noted that a system equipped with

an overhead spray system that periodically cleaned the packing with

fresh water performed much better than a system without such cleaning.

Based on those results, the EPA believes that without the requirement

that makeup water be fresh and added to the top of the packed bed,

scrubbers will not continuously meet the required emission limit even

if the scrubber met the limit during the initial performance test and

is operated within the appropriate ranges of pressure drop and velocity

pressure. For clarification, the term fresh water is defined in the

final rule.

There were 11 comments on the washdown requirements for composite

mesh-pad systems. Several of these commenters indicated that the

specified washdown frequency was either impractical, infeasible, or

unnecessary. Seven commenters suggested washdown requirements for

composite mesh-pad systems be site-specific, as recommended by vendors,

or apply only if pressure drop determinations indicate the potential

presence of chromic acid buildup. Two commenters indicated that the

washdown water will likely exceed the quantity of water that can be

recycled, thus resulting in a wastewater stream that needs to be

treated.

In the final rule, the EPA has revised the requirement that sources

complying with an emission limit by using a composite mesh-pad system

perform washdown of the pads. The EPA believes that washdown is an

essential part of composite mesh-pad system operation; if proper system

maintenance such as washdown does not occur, there will be a decline in

system performance. However, instead of specifying a washdown

frequency, the revised rule specifies that washdown be conducted in

accordance with manufacturers' recommendations as part of a facility's

O&M plan. The EPA recognizes that vendor designs for these systems vary

significantly, and the requirements for washdown are based on the

design of the unit and the operation of the plating tanks. The

frequency of washdown is dependent upon the position of the pad in the

control unit. Pads located in the front portions of the unit are

exposed to higher chromium concentrations and, therefore, require

washdowns more frequently than those located in the back of the unit.

Washdown practices recommended by manufacturers vary from continuous in

some cases to a maximum of once every 1 to 2 weeks.

The EPA has also added work practice standards for fiber-bed mist

eliminators in the final rule because these control devices are likely

to meet the emission limitations, and are known to be in use by sources

affected by these standards. The work practice standards identified for

fiber-bed mist eliminators are analogous to those identified for the

composite mesh-pad system. Washdown requirements for fiber-bed units

will depend on the efficiency of the prefiltering device and the

operation of the plating tanks. Fiber-bed units installed downstream of

more efficient prefiltering systems, such as packed-bed scrubbers, will

require less frequent washdown than those using a less effective

prefiltering device because of the lower inlet loading to the unit.

Most vendors of fiber-bed units recommended monitoring of the pressure

drop as a means of gauging when the unit needs to be washed down. If an

increase in pressure drop is observed, then the unit will be washed

down to remove any chromium built up on the fiber elements.

3. Frequency of Monitoring for Add-on Air Pollution Control Devices

Fourteen commenters indicated that the daily monitoring of add-on

air pollution control devices is unnecessary, particularly for small

sources, and suggested that at least some of the monitoring be required

on only a weekly, monthly, or quarterly basis. [[Page 4959]] Other

commenters suggested that monitoring be tied to production rate, that

monitoring be conducted only on days when electroplating is taking

place, or that monitoring requirements be reduced after the source has

been in compliance for 6 months. Commenters also requested that

monitoring be required only during tank operation, and that tank

operation be defined. Several commenters disagreed with the proposed

inspection frequency because of increased exposure hazards to persons

conducting the inspections or of anticipated down-time due to the

inaccessibility of control systems.

In response to these comments and to minimize the burden on

regulated sources, the EPA has reduced the burden associated with the

compliance monitoring and work practice standards in the final rule.

The final rule continues to require daily monitoring of pressure drop

and velocity pressure for compliance, but the monitoring procedures

specified in the rule are the minimum required to determine continuous

compliance. Once the monitoring devices are in place, the only labor

required is that needed to read the gauges. The frequency of

inspections for compliance with the work practice standards has also

been reduced or revised. In the final rule, the frequency of

inspections has been reduced from monthly or daily to once every 3

months. The EPA believes that the inspections are still necessary to

ensure that system degradation is not occurring over time, because

gradual degradation may not be apparent from compliance monitoring

alone. Some commenters noted that their systems were not accessible for

inspection, or that the inspection would result in extended downtime.

The compliance timeframes in the final rule should allow sources

sufficient time to retrofit their systems to facilitate inspections,

and the negative effects of any downtime are minimized by the reduced

inspection frequency.

The final rule also has been clarified so that monitoring

requirements apply only during tank operation; tank operation is

defined in Sec. 63.341.

4. Compliance Monitoring Associated With Fume Suppressants

Regarding the use of wetting agent-type fume suppressants, seven

commenters indicated that the requirement for maintaining surface

tension below 40 dynes/cm for chromic acid baths is inappropriate. The

reasons provided by the commenters were that a surface tension standard

may not be prudent to demonstrate compliance, a direct correlation

between exceedance of parameters and emission limits has not been

established, and the rule should allow sources to set their own

compliance value for surface tension. Other commenters noted that the

specified limit was either too low or was not consistent with

manufacturers' recommendations.

Based on data collected by the EPA, the performance of an

electroplating bath controlled with a wetting agent-type fume

suppressant can be determined by the surface tension of the bath.

Therefore, the EPA believes that there is a direct link between surface

tension and emissions. The EPA also believes that it is necessary and

appropriate to set a default value for surface tension in the rule.

Based on the EPA's experience, many decorative chromium electroplating

tanks are not ventilated, making source testing impossible without

considerable retrofitting.

The EPA has increased the default surface tension limit from the

proposed 40 dynes/cm to 45 dynes/cm based on information received

during the comment period. However, if a facility believes that a

different surface tension value is appropriate, the rule allows a

source to conduct a performance test concurrently with surface tension

monitoring to establish the maximum surface tension that corresponds to

compliance with the emission limits. The source would subsequently

monitor surface tension, with an exceedance occurring if the surface

tension of the bath exceeded the value measured during the performance

test.

Regarding foam blanket-type fume suppressants, several commenters

were concerned about the technique for measuring foam blanket thickness

and the potential hazards associated with this measurement. Another

commenter stated that the stack testing requirement is unreasonable due

to its excessive cost.

The EPA does not believe that it is necessary to specify a

procedure because it is simply a depth measurement. Specifying a

technique may also hinder the development of site-specific techniques

to reduce worker exposure. The EPA believes that wetting agents are

safer than foam blankets because foam blankets present a potential

safety hazard. The foam traps the hydrogen gas and chromic acid mist in

the foam layer; if these gases build up and a spark is generated, a

hydrogen explosion will result. As a means of encouraging wetting agent

use over foam blankets, sources using wetting agents do not have to

conduct a performance test unless they want to set a surface tension

limit other than the default value of 45 dynes/cm. The EPA believes

that the compliance timeframes in the final rule will allow sources

that currently use foam blankets the opportunity to explore the use of

wetting agents. Sources that wish to continue using foam blankets will

be required to conduct a performance test.

5. Frequency of Monitoring Associated With Fume Suppressants

There were over 20 comments related to the frequency of monitoring

surface tension. Several of these commenters made recommendations for

alternate monitoring schedules, ranging from daily to monthly

monitoring, in place of the 4-hour schedule. Among the reasons cited

for decreasing the surface tension monitoring frequency were that

surface tension does not change on a daily or weekly basis, measuring

surface tension is very time-consuming and could require someone full-

time if there were multiple tanks, and frequent monitoring results in

increased worker exposure.

Thirteen commenters provided remarks regarding the burden of hourly

testing for sources using foam blankets. The commenters noted that foam

blankets that are used according to manufacturer's instructions are

designed to last 24 hours provided the air is not agitated at the

surface near the anodes and freeboard height is adequate. Therefore,

visual observation is adequate for determining foam blanket

effectiveness. Other commenters stated that the excessive monitoring

requirements for foam blankets discourage their use, yet several States

recommend or require foam blankets with less testing and recordkeeping

than that proposed by the EPA.

In response to comments and some data received, the EPA recognizes

that the 4-hour surface tension monitoring frequency specified in the

proposed rule may be burdensome, and in some cases, unnecessary. The

EPA has insufficient data, however, to establish the monitoring

frequency that is appropriate for each mode of bath operation.

Therefore, the final rule allows a decrease in monitoring frequency if

no exceedances occur. Section 63.343(c)(5)(ii)(B) specifies that the

surface tension be measured once every 4-hours of tank operation for

the first 40 hours of tank operation after the compliance date. If no

exceedances occur, monitoring can occur once every 8 hours of tank

operation. Once there are again no exceedances during 40 hours of tank

operation, surface tension measurement may be conducted once every 40

hours of tank operation on an on-going basis, until an exceedance

occurs. Once an exceedance of the [[Page 4960]] standard occurs or the

electroplating solution is changed out, the original monitoring

schedule must be resumed.

Likewise, the final rule contains allowances to decrease the

frequency of monitoring foam blanket thickness. The proposed hourly

frequency is based on the EPA's experience that foam blankets can

deplete quickly and must be closely monitored. The final rule is

unchanged in that sources using a foam blanket must conduct a

performance test, and the initial monitoring frequency is once per

hour. However, as with wetting agents, the final rule allows a decrease

in monitoring frequency if no exceedances occur. Section

63.343(c)(6)(ii)(B) specifies that the foam blanket thickness be

measured once every hour of tank operation for the first 40 hours of

tank operation after the compliance date. If no exceedances occur, the

time between monitoring may be increased to once every 4 hours of tank

operation. Once there are no exceedances during 40 hours of tank

operation, foam blanket thickness measurement may be conducted once

every 8 hours of tank operation on an on-going basis. As with wetting

agents, if there is an exceedance or if the electroplating bath is

changed out, the original monitoring schedule must be resumed.

I. Selection of Test Methods

Three commenters requested that CARB Method 425 be evaluated for

equivalency, and if determined to be equivalent, be identified as such

in the rule. These commenters also stated that sources that have

performed this test should not have to retest. Four commenters asked

whether retesting will be required if sources have conducted

performance tests previously using 306, 306A, or an equivalent test

method.

Section 63.344(c)(2) identifies the conditions under which the CARB

Method 425 is considered equivalent. Basically, the acceptability of

this test method will depend upon the analysis rather than the sampling

train or sampling procedure. Regarding the issue of whether retesting

is required, Sec. 63.344(b) of the final rule outlines the criteria

that must be met for a previous source test to be acceptable.

Two commenters requested that the rule provide guidance on how to

verify compliance when both chromium anodizing and hard chromium

electroplating tanks are vented to a common control device. Three

commenters pointed out that the regulation does not account for the

situation in which chromium electroplating sources share a ventilation

system with nonchromium sources that could introduce dilution air.

Three commenters noted that it is extremely difficult to reconfigure

some existing systems in such a way that only the emissions from

chromium electroplating or anodizing are tested.

There are basically two situations involving multiple tanks

manifolded to one control system: (1) The multiple tanks include a

chromium electroplating or chromium anodizing tank among other tanks

not affected by the rule; or (2) the multiple tanks include chromium

tanks performing different operations (e.g., electroplating and

anodizing) or hard chromium tanks subject to different emission limits

(e.g., a new tank and an existing small tank), which may or may not be

controlled with nonaffected sources. Section 63.344(e) of the final

rule includes compliance provisions for both of these situations.

J. Selection of Reporting and Recordkeeping Requirements

Several commenters stated that the frequency of recordkeeping and

reporting outlined in the proposed rule was overly burdensome and

suggested several alternatives. Seven commenters stated that the types

of recordkeeping required by the rule are inappropriate. In general,

the commenters remarked that records, such as the amount of chemicals

used and purchased and the amount of fume suppressant material added do

not indicate compliance. Two commenters stated that recordkeeping

requirements be limited to only surface tension measurements because

that measurement is the basis of compliance. One commenter indicated

there is no environmental benefit to keeping records of gas velocities,

pressure drops, washdown conditions, and scrubber water chromium

concentrations. Two commenters stated that maintaining records at a

facility for 5 years is excessive; a more appropriate length of time

would be 3 years. One commenter suggested a minimum of 2 years.

Two commenters suggested that the reporting schedule be replaced

with a requirement that the source submit an annual certification that

necessary control parameters have been met, consistent with the annual

certification requirements of title V. Another commenter indicated that

sources should not be required to submit compliance reports if the

source's permitting agency inspects the onsite records annually.

Finally, one commenter suggested that the rule allow a reduced

reporting frequency after 2 years if sources do not experience

exceedances of any State or Federal emission standards.

Seven commenters stated that the costs associated with the

monitoring and recordkeeping constituted an unnecessary burden to both

large and small facilities. These commenters also noted that the EPA

underestimated the costs associated with monitoring, reporting, and

recordkeeping. Two of the commenters stated that small businesses do

not have the resources to keep extensive records. Another commenter

pointed out that the EPA has recognized differences in large and small

facilities in selecting MACT emission standards and should also

recognize differences between large and small facilities in selecting

reporting, recordkeeping, and permitting requirements.

To respond to comments received and to reduce the burden on the

many area sources that will be subject to these standards, the

monitoring, reporting, and recordkeeping requirements have been reduced

in the final rule to the extent possible while still providing the EPA

with the ability to determine a source's continuous compliance status.

The recordkeeping requirements are contained in Sec. 63.346 of the

final rule. The EPA concurs that the records required to be kept should

correspond specifically to that which is required to demonstrate

compliance. As such, recordkeeping associated with fume suppressants

requires only that sources maintain records of the date and time of

surface tension or foam blanket thickness measurements, as appropriate,

the value measured, and the date and time of additions of fume

suppressant to the bath. Likewise, the recordkeeping associated with

the add-on air pollution control devices is reduced to the extent that

the monitoring requirements have been reduced. Sources will have to

keep records of pressure drop and velocity pressure, as appropriate, as

well as records to document adherence with the O&M plan required by

Sec. 63.342(f)(3).

The final rule is unchanged from proposal in that it requires that

owners or operators of affected sources maintain records for a period

of 5 years following each occurrence, measurement, maintenance,

corrective action, report, or record. This requirement is consistent

with the General Provisions and with the title V permit program. The

EPA believes retention of records for 5 years allows the EPA to

establish a source's history and pattern of compliance for purposes of

determining the appropriate level of enforcement action.

The final rule also requires submission of on-going compliance

status reports to document whether a [[Page 4961]] source has been in

continuous compliance with the standards. The final rule contains

different reporting schedules for major and area sources. Major sources

are required to submit on-going compliance status reports semiannually,

unless an exceedance occurs, at which time quarterly reports would be

required. This change is analogous to the requirements of the final

General Provisions, which had only been proposed at the time of this

proposed rulemaking.

In an effort to reduce the burden on area sources, the final rule

allows area sources to complete an annual compliance report, and allows

the source to maintain the report on site, to be made available to the

Administrator or permitting authority upon request. The EPA recognizes

that many permitting authorities may not be equipped to handle reports

from area sources, and that these sources may not be the sources of

primary concern to the authority. However, the requirements in the

final rule do not alleviate affected area sources from complying with

the reporting requirements of State or Federal operating permit

programs under title V. The rule does require that area sources submit

reports semiannually if exceedances occur, or if required by the

Administrator or permitting authority.

Sources using a trivalent chromium bath are only required to keep

records of the bath ingredients purchased. These sources must submit an

initial notification and notification of compliance status, but are not

required to submit on-going compliance status reports.

As a result of the reduced monitoring, reporting, and recordkeeping

in the final rule compared to the proposed rule, the costs of these

activities have also been reduced. A comparison of the cost of the

monitoring, reporting, and recordkeeping associated with the final and

proposed rules was presented in section III.B of this preamble for each

of the regulated source categories.

One commenter requested that the rule clearly state which sections

of the General Provisions apply to chromium electroplating sources and

which do not apply. To eliminate confusion concerning the applicability

of the General Provisions to this source category, Table 1 of subpart N

lists which of the General Provisions to part 63 apply and which do not

apply to affected sources.

K. Operating Permit Program

Eleven commenters stated that area sources should not be required

to obtain title V operating permits because the costs for area sources

to obtain title V permits would be overly burdensome, and the emissions

from these sources may be insignificant. Three of these commenters

suggested that the rule explicitly state that a permit is required only

for applicable emissions units at nonmajor sources. Two commenters

asked that a general permit be included in the final rule to reduce the

burden for small facilities. Another commenter stated that a title V

permit is not necessary because existing requirements are enforceable

through State and local permits. This commenter and one other commenter

pointed out that because area sources are not likely to be subject to

multiple MACT standards or to employ emissions averaging and complex

alternate operating scenarios, title V permits do not benefit the area

sources.

Two commenters stated that in preparing their title V permit

programs, States did not anticipate a need for emission-unit specific

permits at nonmajor sources, and inclusion of nonmajor sources under

title V will require that many local agencies revise their permit

programs. Two other commenters stated that States will not have the

resources for completing title V permits for area sources; some states

have exempted nonmajor sources from their permitting programs until the

nonmajor source permitting rule is promulgated in the late 1990's.

The EPA believes that requiring all sources that are subject to the

standards, including area sources, to obtain title V operating permits

is important because of the toxicity of chromium compounds and the

close proximity of many of these sources to residential areas. The EPA

believes that permitting area sources will not be overly burdensome to

permitting authorities and affected sources for the reasons given

below.

First, many States are already permitting these sources under their

State permit programs. The preamble to the final part 70 rule states

that ``some nonmajor sources would already be permitted at the State

level, and therefore would have some experience with the permitting

process and completing permit applications.'' Therefore, a State would

have little reason to defer title V permitting of sources that already

have State operating permits. Second, the burden may be reduced

significantly by issuing general permits to these sources. According to

the preamble to the final part 70 rule, general permits ``* * * provide

an alternative means for permitting sources for which the procedures of

the normal permitting process would be overly burdensome, such as area

sources under section 112* * *'' Under this option, States would

develop a single general permit for this source category and issue it

to individual sources; or alternatively, a letter or certification may

be used. The burden would also be reduced by using general permits

because public participation and the EPA and affected State review is

only necessary when the initial general permit is drafted and issued.

When subsequent general permits are issued to individual sources, these

activities are not required. Finally, States are developing small

business assistance programs (SBAP's) to assist these types of sources

with the permitting process that will be funded using the annual fees

collected from permitted sources. Small businesses may also be eligible

for reduced permitting fees. Also, the EPA is developing a guidance

document, scheduled to be completed by January 1995, which will include

sample forms for monitoring, recordkeeping, and reporting requirements,

and a simplified general operating permit.

Under title V, sources must include information on all emission

points (except those considered insignificant under the State or local

permit program) in their permit application. However, only these

emission points that are subject to regulation will be addressed in the

permit.

VI. Administrative Requirements

A. Docket

The docket for this rulemaking is A-88-02. The docket is an

organized and complete file of all the information submitted to or

otherwise considered by the EPA in the development of this rulemaking.

The principal purposes of the docket are: (1) To allow interested

parties a means to identify and locate documents so that they can

effectively participate in the rulemaking process; and (2) to serve as

the record in case of judicial review (except for interagency review

materials) [section 307(d)(7)(A) of the Act]. The docket is available

for public inspection at the EPA's Air and Radiation Docket and

Information Center, the location of which is given in the ADDRESSES

section of this notice.

B. Executive Order 12866

Under Executive Order 12866 [58 FR 51735 (October 4, 1993)], the

Agency must determine whether the regulatory action is ``significant''

and therefore subject to OMB review and the requirements of the

Executive Order. The Order defines ``significant regulatory action'' as

one that is likely to result in a rule that may: [[Page 4962]]

(1) Have an annual effect on the economy of $100 million or more,

or adversely affect in a material way the economy, a sector of the

economy, productivity, competition, jobs, the environment, public

health or safety, or State, local, or tribal governments or

communities;

(2) Create a serious inconsistency or otherwise interfere with an

action taken or planned by another agency;

(3) Materially alter the budgetary impact of entitlements, grants,

user fees, or loan programs or the rights and obligations of recipients

thereof; or

(4) Raise novel legal or policy issues arising out of legal

mandates, the President's priorities, or the principles set forth in

the Executive Order.

Pursuant to the terms of the Executive Order 12866, the Office of

Management and Budget (OMB) has notified the EPA that this action is a

``significant regulatory action'' within the meaning of the Executive

Order. For this reason, this action was sent to OMB for review. Changes

made in response to OMB suggestions or recommendations will be

documented in the public record.

C. Paperwork Reduction Act

Information collection requirements associated with this rule have

been approved by OMB under the provisions of the Paperwork Reduction

Act of 1980, 44 U.S.C. 3501 et seq., and have been assigned OMB control

number 2060-0327. An Information Collection Request (ICR) document has

been prepared by the EPA (ICR No. 1611.02) to reflect the changed

information requirements of the final rule and has been submitted to

OMB for review. A copy may be obtained from Sandy Farmer, Information

Policy Branch, EPA, 401 M Street, SW. (2136), Washington, DC 20460, or

by calling (202) 260-2740.

The public reporting burden for this collection of information is

estimated to average 34 hours per respondent in the first year, 117

hours per respondent in the second year, and 297 hours per respondent

in the third year. This estimate includes the time required for

reviewing instructions, searching existing data sources, gathering and

maintaining the data needed, and completing and reviewing the

collection of information. The burden is greatest in the second and

third years because this is when performance tests will be conducted.

An on-going burden of 104 hours per respondent is representative of the

burden following the third year.

Send comments regarding the burden estimate or any other aspect of

this collection of information, including suggestions for reducing this

burden, to Chief, Information Policy Branch, EPA, 401 M Street, SW.

(2136), Washington, DC 20460; and to the Office of Information and

Regulatory Affairs, Office of Management and Budget, Washington, DC

20503, marked ``Attention: Desk Officer for EPA.''

D. Regulatory Flexibility Act

The Regulatory Flexibility Act of 1980 (5 U.S.C. 601 et seq.)

requires that a Regulatory Flexibility Analysis be performed for all

rules that have ``significant impact on a substantial number of small

entities.'' If a preliminary analysis indicates that a proposed

regulation would have a significant economic impact on 20 percent or

more of small entities, then a regulatory flexibility analysis must be

prepared.

Present Regulatory Flexibility Act guidelines define an economic

impact as significant if it meets one of the following criteria:

(1) Compliance increases annual production costs by more than 5

percent, assuming costs are passed on to consumers;

(2) Compliance costs as a percentage of sales for small entities

are at least 10 percent more than compliance costs as a percentage of

sales for large entities;

(3) Capital costs of compliance represent a ``significant'' portion

of capital available to small entities, considering internal cash flow

plus external financial capabilities; or

(4) Regulatory requirements are likely to result in closures of

small entities.

Using the Small Business Administration's definition of a small

business for SIC Code 3471 of less than 500 employees, it has been

determined that none of the above criteria are triggered. In the hard

chromium electroplating source category, the number of small businesses

is estimated to be 1,170. None of the regulatory alternatives

considered will significantly impact 20 percent of this operation. For

example, the estimated number of closures is approximated as less than

5 percent. Likewise, the standards for decorative chromium

electroplaters and chromium anodizers would not cause any of the above

criteria to be triggered.

Pursuant to the provisions of 5 U.S.C. 605(b), I hereby certify

that this rule will not have a significant economic impact on a

substantial number of small business entities because the number of

small business entities that would be affected is not significant.

E. Miscellaneous

In accordance with section 117 of the Act, publication of this

promulgated rule was preceded by consultation with appropriate advisory

committees, independent experts, and Federal departments and agencies.

This regulation will be reviewed 8 years from the date of

promulgation. This review will include an assessment of such factors as

evaluation of the residual health risks, any overlap with other

programs, the existence of alternative methods, enforceability,

improvements in emission control technology and health data, and the

recordkeeping and reporting requirements.

List of Subjects in 40 CFR Parts 9 and 63

Environmental protection, Air pollution control, Hazardous

substances, Incorporation by reference, Reporting and recordkeeping

requirements.

Dated: November 22, 1994.

Carol M. Browner,

Administrator.

For the reasons set out in the preamble, title 40, Chapter I of the

Code of Federal Regulations is amended as set forth below.

PART 9--[AMENDED]

1. The authority citation for part 9 continues to read as follows:

Authority: 7 U.S.C. 135 et seq., 1235-136y; 15 U.S.C. 2001,

2003, 2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C.

9701; 33 U.S.C. 1251 et seq., 1311, 1313d, 1314, 1321, 1326, 1330,

1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR, 1971-

1975; Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 300g-

1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3,

300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-

9657, 11023, 11048.

2. Section 9.1 is amended by adding a new entry to the table under

the indicated heading in numerical order to read as follows:

Sec. 9.1 OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------

OMB control

40 CFR citation No.

------------------------------------------------------------------------

* * * * *

National Emission Standards for Hazardous Air Pollutants

for Source Categories:

* * * * *

63.345-63.347.............................................. 2060-0327

* * * * *

------------------------------------------------------------------------

[[Page 4963]] PART 63--[AMENDED]

1. The authority citation for part 63 continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

2. Section 63.14 is amended by adding paragraphs (b) (4) and (5) to

read as follows:

Sec. 63.14 Incorporation by reference.

* * * * *

(b) * * *

(4) ASTM D 1193-77, Standard Specification for Reagent Water, IBR

approved for Method 306, section 4.1.1 and section 4.4.2, of appendix A

to part 63.

(5) ASTM D 1331-89, Standard Test Methods for Surface and

Interfacial Tension of Solutions of Surface Active Agents, IBR approved

for Method 306B, section 2.2, section 3.1, and section 4.2, of appendix

A to part 63.

* * * * *

3. By adding a new subpart N to read as follows:

Subpart N--National Emission Standards for Chromium Emissions From Hard

and Decorative Chromium Electroplating and Chromium Anodizing Tanks

Sec.

63.340 Applicability and designation of sources.

63.341 Definitions and nomenclature.

63.342 Standards.

63.343 Compliance provisions.

63.344 Performance test requirements and test methods.

63.345 Provisions for new and reconstructed sources.

63.346 Recordkeeping requirements.

63.347 Reporting requirements.

Table 1 to Subpart N of Part 63--General Provisions Applicability to

Subpart N

Subpart N--National Emission Standards for Chromium Emissions From

Hard and Decorative Chromium Electroplating and Chromium Anodizing

Tanks

Sec. 63.340 Applicability and designation of sources.

(a) The affected source to which the provisions of this subpart

apply is each chromium electroplating or chromium anodizing tank at

facilities performing hard chromium electroplating, decorative chromium

electroplating, or chromium anodizing.

(b) Owners or operators of affected sources subject to the

provisions of this subpart must also comply with the requirements of

subpart A of this part, according to the applicability of subpart A of

this part to such sources, as identified in Table 1 of this subpart.

(c) Process tanks associated with a chromium electroplating or

chromium anodizing process, but in which neither chromium

electroplating nor chromium anodizing is taking place, are not subject

to the provisions of this subpart. Examples of such tanks include, but

are not limited to, rinse tanks, etching tanks, and cleaning tanks.

Likewise, tanks that contain a chromium solution, but in which no

electrolytic process occurs, are not subject to this subpart. An

example of such a tank is a chrome conversion coating tank where no

electrical current is applied.

(d) Affected sources in which research and laboratory operations

are performed are exempt from the provisions of this subpart when such

operations are taking place.

(e) The owner or operator of an affected source subject to the

requirements of this subpart is required to obtain a title V permit

from the permitting authority in which the affected source is located.

Sec. 63.341 Definitions and nomenclature.

(a) Definitions. Terms used in this subpart are defined in the Act,

in subpart A of this part, or in this section. For the purposes of

subpart N of this part, if the same term is defined in subpart A of

this part and in this section, it shall have the meaning given in this

section.

Add-on air pollution control device means equipment installed in

the ventilation system of chromium electroplating and anodizing tanks

for the purposes of collecting and containing chromium emissions from

the tank(s).

Air pollution control technique means any method, such as an add-on

air pollution control device or a chemical fume suppressant, that is

used to reduce chromium emissions from chromium electroplating and

chromium anodizing tanks.

Base metal means the metal or metal alloy that comprises the

workpiece.

Bath component means the trade or brand name of each component(s)

in trivalent chromium plating baths. For trivalent chromium baths, the

bath composition is proprietary in most cases. Therefore, the trade or

brand name for each component(s) can be used; however, the chemical

name of the wetting agent contained in that component must be

identified.

Chemical fume suppressant means any chemical agent that reduces or

suppresses fumes or mists at the surface of an electroplating or

anodizing bath; another term for fume suppressant is mist suppressant.

Chromic acid means the common name for chromium anhydride

(CrO3).

Chromium anodizing means the electrolytic process by which an oxide

layer is produced on the surface of a base metal for functional

purposes (e.g., corrosion resistance or electrical insulation) using a

chromic acid solution. In chromium anodizing, the part to be anodized

acts as the anode in the electrical circuit, and the chromic acid

solution, with a concentration typically ranging from 50 to 100 grams

per liter (g/L), serves as the electrolyte.

Chromium electroplating or chromium anodizing tank means the

receptacle or container in which hard or decorative chromium

electroplating or chromium anodizing occurs.

Composite mesh-pad system means an add-on air pollution control

device typically consisting of several mesh-pad stages. The purpose of

the first stage is to remove large particles. Smaller particles are

removed in the second stage, which consists of the composite mesh pad.

A final stage may remove any reentrained particles not collected by the

composite mesh pad.

Decorative chromium electroplating means the process by which a

thin layer of chromium (typically 0.003 to 2.5 microns) is

electrodeposited on a base metal, plastic, or undercoating to provide a

bright surface with wear and tarnish resistance. In this process, the

part(s) serves as the cathode in the electrolytic cell and the solution

serves as the electrolyte. Typical current density applied during this

process ranges from 540 to 2,400 Amperes per square meter (A/m2)

for total plating times ranging between 0.5 to 5 minutes.

Electroplating or anodizing bath means the electrolytic solution

used as the conducting medium in which the flow of current is

accompanied by movement of metal ions for the purposes of

electroplating metal out of the solution onto a workpiece or for

oxidizing the base material.

Emission limitation means, for the purposes of this subpart, the

concentration of total chromium allowed to be emitted expressed in

milligrams per dry standard cubic meter (mg/dscm), or the allowable

surface tension expressed in dynes per centimeter (dynes/cm).

Facility means the major or area source at which chromium

electroplating or chromium anodizing is performed.

Fiber-bed mist eliminator means an add-on air pollution control

device that removes contaminants from a gas stream through the

mechanisms of inertial impaction and Brownian diffusion. These devices

are typically installed downstream of another control device, which

serves to prevent plugging, and [[Page 4964]] consist of one or more

fiber beds. Each bed consists of a hollow cylinder formed from two

concentric screens; the fiber between the screens may be fabricated

from glass, ceramic plastic, or metal.

Foam blanket means the type of chemical fume suppressant that

generates a layer of foam across the surface of a solution when current

is applied to that solution.

Fresh water means water, such as tap water, that has not been

previously used in a process operation or, if the water has been

recycled from a process operation, it has been treated and meets the

effluent guidelines for chromium wastewater.

Hard chromium electroplating or industrial chromium electroplating

means a process by which a thick layer of chromium (typically 1.3 to

760 microns) is electrodeposited on a base material to provide a

surface with functional properties such as wear resistance, a low

coefficient of friction, hardness, and corrosion resistance. In this

process, the part serves as the cathode in the electrolytic cell and

the solution serves as the electrolyte. Hard chromium electroplating

process is performed at current densities typically ranging from 1,600

to 6,500 A/m2 for total plating times ranging from 20 minutes to

36 hours depending upon the desired plate thickness.

Hexavalent chromium means the form of chromium in a valence state

of +6.

Large, hard chromium electroplating facility means a facility that

performs hard chromium electroplating and has a maximum cumulative

potential rectifier capacity greater than or equal to 60 million

ampere-hours per year (amp-hr/yr).

Maximum cumulative potential rectifier capacity means the summation

of the total installed rectifier capacity associated with the hard

chromium electroplating tanks at a facility, expressed in amperes,

multiplied by the maximum potential operating schedule of 8,400 hours

per year and 0.7, which assumes that electrodes are energized 70

percent of the total operating time. The maximum potential operating

schedule is based on operating 24 hours per day, 7 days per week, 50

weeks per year.

Operating parameter value means a minimum or maximum value

established for a control device or process parameter which, if

achieved by itself or in combination with one or more other operating

parameter values, determines that an owner or operator is in continual

compliance with the applicable emission limitation or standard.

Packed-bed scrubber means an add-on air pollution control device

consisting of a single or double packed bed that contains packing media

on which the chromic acid droplets impinge. The packed-bed section of

the scrubber is followed by a mist eliminator to remove any water

entrained from the packed-bed section.

Research or laboratory operation means an operation whose primary

purpose is for research and development of new processes and products,

that is conducted under the close supervision of technically trained

personnel, and that is not involved in the manufacture of products for

commercial sale in commerce, except in a de minimis manner.

Small, hard chromium electroplating facility means a facility that

performs hard chromium electroplating and has a maximum cumulative

potential rectifier capacity less than 60 million amp-hr/yr.

Stalagmometer means a device used to measure the surface tension of

a solution.

Surface tension means the property, due to molecular forces, that

exists in the surface film of all liquids and tends to prevent liquid

from spreading.

Tank operation means the time in which current and/or voltage is

being applied to a chromium electroplating tank or a chromium anodizing

tank.

Tensiometer means a device used to measure the surface tension of a

solution.

Trivalent chromium means the form of chromium in a valence state of

+3.

Trivalent chromium process means the process used for

electrodeposition of a thin layer of chromium onto a base material

using a trivalent chromium solution instead of a chromic acid solution.

Wetting agent means the type of chemical fume suppressant that

reduces the surface tension of a liquid.

(b) Nomenclature. The nomenclature used in this subpart has the

following meaning:

(1) AMR=the allowable mass emission rate from each type of affected

source subject to the same emission limitation in milligrams per hour

(mg/hr).

(2) AMRsys=the allowable mass emission rate from affected

sources controlled by an add-on air pollution control device

controlling emissions from multiple sources in mg/hr.

(3) EL=the applicable emission limitation from Sec. 63.342 in

milligrams per dry standard cubic meter (mg/dscm).

(4) IAtotal=the sum of all inlet duct areas from both affected

and nonaffected sources in meters squared.

(5) IDAi=the total inlet area for all ducts associated with

affected sources in meters squared.

(6) IDAi,a=the total inlet duct area for all ducts conveying

chromic acid from each type of affected source performing the same

operation, or each type of affected source subject to the same emission

limitation in meters squared.

(7) VR=the total of ventilation rates for each type of affected

source subject to the same emission limitation in dry standard cubic

meters per minute (dscm/min).

(8) VRinlet=the total ventilation rate from all inlet ducts

associated with affected sources in dscm/min.

(9) VRinlet,a=the total ventilation rate from all inlet ducts

conveying chromic acid from each type of affected source performing the

same operation, or each type of affected source subject to the same

emission limitation in dscm/min.

(10) VRtot=the average total ventilation rate for the three

test runs as determined at the outlet by means of the Method 306 in

appendix A of this part testing in dscm/min.

Sec. 63.342 Standards.

(a) Each owner or operator of an affected source subject to the

provisions of this subpart shall comply with these requirements on and

after the compliance dates specified in Sec. 63.343(a). All affected

sources are regulated by applying maximum achievable control

technology.

(b) Applicability of emission limits. (1) The emission limitations

in this section apply only during tank operation, and also apply during

periods of startup and shutdown as these are routine occurrences for

affected sources subject to this subpart. The emission limitations do

not apply during periods of malfunction, but the work practice

standards that address operation and maintenance and that are required

by paragraph (f) of this section must be followed during malfunctions.

(2) If an owner or operator is controlling a group of tanks with a

common add-on air pollution control device, the emission limitations of

paragraphs (c), (d), and (e) of this section apply whenever any one

affected source is operated. The emission limitation that applies to

the group of affected sources is:

(i) The emission limitation identified in paragraphs (c), (d), and

(e) of this section if the affected sources are performing the same

type of operation (e.g., hard chromium electroplating), are subject to

the same emission limitation, and are not controlled by an add-on air

pollution control device also controlling nonaffected

sources; [[Page 4965]]

(ii) The emission limitation calculated according to

Sec. 63.344(e)(3) if affected sources are performing the same type of

operation, are subject to the same emission limitation, and are

controlled with an add-on air pollution control device that is also

controlling nonaffected sources; and

(iii) The emission limitation calculated according to

Sec. 63.344(e)(4) if affected sources are performing different types of

operations, or affected sources are performing the same operations but

subject to different emission limitations, and are controlled with an

add-on air pollution control device that may also be controlling

emissions from nonaffected sources.

(c)(1) Standards for hard chromium electroplating tanks. During

tank operation, each owner or operator of an existing, new, or

reconstructed affected source shall control chromium emissions

discharged to the atmosphere from that affected source by not allowing

the concentration of total chromium in the exhaust gas stream

discharged to the atmosphere to exceed:

(i) 0.015 milligrams of total chromium per dry standard cubic meter

(mg/dscm) of ventilation air (6.6 x 10-6 grains per dry standard

cubic foot [gr/dscf]); or

(ii) 0.03 mg/dscm (1.3 x 10-5 gr/dscf) if the hard chromium

electroplating tank is an existing affected source and is located at a

small, hard chromium electroplating facility.

(2)(i) An owner or operator may demonstrate the size of a hard

chromium electroplating facility through the definitions in

Sec. 63.341(a). Alternatively, an owner or operator of a facility with

a maximum cumulative potential rectifier capacity of 60 million amp-hr/

yr or more may be considered small if the actual cumulative rectifier

capacity is less than 60 million amp-hr/yr as demonstrated using the

following procedures:

(A) If records show that the facility's previous annual actual

rectifier capacity was less than 60 million amp-hr/yr, by using

nonresettable ampere-hr meters and keeping monthly records of actual

ampere-hr usage for each 12-month rolling period following the

compliance date in accordance with Sec. 63.346(b)(12). The actual

cumulative rectifier capacity for the previous 12-month rolling period

shall be tabulated monthly by adding the capacity for the current month

to the capacities for the previous 11 months; or

(B) By accepting a Federally-enforceable limit on the maximum

cumulative potential rectifier capacity of a hard chromium

electroplating facility through the title V permit required by

Sec. 63.340(e), and by maintaining monthly records in accordance with

Sec. 63.346(b)(12) to demonstrate that the limit has not been exceeded.

The actual cumulative rectifier capacity for the previous 12-month

rolling period shall be tabulated monthly by adding the capacity for

the current month to the capacities for the previous 11 months.

(ii) Once the monthly records required to be kept by

Sec. 63.346(b)(12) and by this paragraph show that the actual

cumulative rectifier capacity over the previous 12-month rolling period

corresponds to the large designation, the owner or operator is subject

to the emission limitation identified in paragraph (c)(1)(i) of this

section, in accordance with the compliance schedule of

Sec. 63.343(a)(5).

(d) Standards for decorative chromium electroplating tanks using a

chromic acid bath and chromium anodizing tanks. During tank operation,

each owner or operator of an existing, new, or reconstructed affected

source shall control chromium emissions discharged to the atmosphere

from that affected source by either:

(1) Not allowing the concentration of total chromium in the exhaust

gas stream discharged to the atmosphere to exceed 0.01 mg/dscm

(4.4 x 10-6 gr/dscf); or

(2) If a chemical fume suppressant containing a wetting agent is

used, by not allowing the surface tension of the electroplating or

anodizing bath contained within the affected source to exceed 45 dynes

per centimeter (dynes/cm) (3.1 x 10-3 pound-force per foot

[lbf/ft]) at any time during operation of the tank.

(e) Standards for decorative chromium electroplating tanks using a

trivalent chromium bath. (1) Each owner or operator of an existing,

new, or reconstructed decorative chromium electroplating tank that uses

a trivalent chromium bath that incorporates a wetting agent as a bath

ingredient is subject to the recordkeeping and reporting requirements

of Secs. 63.346(b)(14) and 63.347(i), but are not subject to the work

practice requirements of paragraph (f) of this section, or the

continuous compliance monitoring requirements in Sec. 63.343(c). The

wetting agent must be an ingredient in the trivalent chromium bath

components purchased from vendors.

(2) Each owner or operator of an existing, new, or reconstructed

decorative chromium electroplating tank that uses a trivalent chromium

bath that does not incorporate a wetting agent as a bath ingredient is

subject to the standards of paragraph (d) of this section.

(3) Each owner or operator of existing, new, or reconstructed

decorative chromium electroplating tank that had been using a trivalent

chromium bath that incorporates a wetting agent and ceases using this

type of bath must fulfill the reporting requirements of

Sec. 63.347(i)(3) and comply with the applicable emission limitation

within the timeframe specified in Sec. 63.343(a)(7).

(f) Work practice standards. The work practice standards of this

section address operation and maintenance practices. All owners or

operators subject to the standards in paragraphs (c) and (d) of this

section are subject to these work practice standards.

(1)(i) At all times, including periods of startup, shutdown, and

malfunction, owners or operators shall operate and maintain any

affected source, including associated air pollution control devices and

monitoring equipment, in a manner consistent with good air pollution

control practices, consistent with the operation and maintenance plan

required by paragraph (f)(3) of this section.

(ii) Malfunctions shall be corrected as soon as practicable after

their occurrence in accordance with the operation and maintenance plan

required by paragraph (f)(3) of this section.

(iii) Operation and maintenance requirements established pursuant

to section 112 of the Act are enforceable independent of emissions

limitations or other requirements in relevant standards.

(2)(i) Determination of whether acceptable operation and

maintenance procedures are being used will be based on information

available to the Administrator, which may include, but is not limited

to, monitoring results; review of the operation and maintenance plan,

procedures, and records; and inspection of the source.

(ii) Based on the results of a determination made under paragraph

(f)(2)(i) of this section, the Administrator may require that an owner

or operator of an affected source make changes to the operation and

maintenance plan required by paragraph (f)(3) of this section for that

source. Revisions may be required if the Administrator finds that the

plan:

(A) Does not address a malfunction that has occurred;

(B) Fails to provide for the operation of the affected source, the

air pollution control techniques, or the control system and process

monitoring equipment during a malfunction in a manner consistent with

good air pollution control practices; or [[Page 4966]]

(C) Does not provide adequate procedures for correcting

malfunctioning process equipment, air pollution control techniques, or

monitoring equipment as quickly as practicable.

(3) Operation and maintenance plan. (i) The owner or operator of an

affected source subject to the work practices of paragraph (f) of this

section shall prepare an operation and maintenance plan to be

implemented no later than the compliance date. The plan shall be

incorporated by reference into the source's title V permit and shall

include the following elements:

(A) The plan shall specify the operation and maintenance criteria

for the affected source, the add-on air pollution control device (if

such a device is used to comply with the emission limits), and the

process and control system monitoring equipment, and shall include a

standardized checklist to document the operation and maintenance of

this equipment;

(B) For sources using an add-on air pollution control device or

monitoring equipment to comply with this subpart, the plan shall

incorporate the work practice standards for that device or monitoring

equipment, as identified in Table 1 of this section, if the specific

equipment used is identified in Table 1 of this section;

(C) If the specific equipment used is not identified in Table 1 of

this section, the plan shall incorporate proposed work practice

standards. These proposed work practice standards shall be submitted to

the Administrator for approval as part of the submittal required under

Sec. 63.343(d);

(D) The plan shall specify procedures to be followed to ensure that

equipment or process malfunctions due to poor maintenance or other

preventable conditions do not occur; and

(E) The plan shall include a systematic procedure for identifying

malfunctions of process equipment, add-on air pollution control

devices, and process and control system monitoring equipment and for

implementing corrective actions to address such malfunctions.

(ii) If the operation and maintenance plan fails to address or

inadequately addresses an event that meets the characteristics of a

malfunction at the time the plan is initially developed, the owner or

operator shall revise the operation and maintenance plan within 45 days

after such an event occurs. The revised plan shall include procedures

for operating and maintaining the process equipment, add-on air

pollution control device, or monitoring equipment during similar

malfunction events, and a program for corrective action for such

events.

(iii) Recordkeeping associated with the operation and maintenance

plan is identified in Sec. 63.346(b). Reporting associated with the

operation and maintenance plan is identified in Sec. 63.347 (g) and (h)

and paragraph (f)(3)(iv) of this section.

(iv) If actions taken by the owner or operator during periods of

malfunction are inconsistent with the procedures specified in the

operation and maintenance plan required by paragraph (f)(3)(i) of this

section, the owner or operator shall record the actions taken for that

event and shall report such actions within 2 working days after

commencing actions inconsistent with the plan. This report shall be

followed by a letter within 7 working days after the end of the event,

unless the owner or operator makes alternative reporting arrangements,

in advance, with the Administrator.

(v) The owner or operator shall keep the written operation and

maintenance plan on record after it is developed to be made available

for inspection, upon request, by the Administrator for the life of the

affected source or until the source is no longer subject to the

provisions of this subpart. In addition, if the operation and

maintenance plan is revised, the owner or operator shall keep previous

(i.e., superseded) versions of the operation and maintenance plan on

record to be made available for inspection, upon request, by the

Administrator for a period of 5 years after each revision to the plan.

(vi) To satisfy the requirements of paragraph (f)(3) of this

section, the owner or operator may use applicable standard operating

procedure (SOP) manuals, Occupational Safety and Health Administration

(OSHA) plans, or other existing plans, provided the alternative plans

meet the requirements of this section.

(g) The standards in this section that apply to chromic acid baths

shall not be met by using a reducing agent to change the form of

chromium from hexavalent to trivalent.

Sec. 63.343 Compliance provisions.

(a) Compliance dates. (1) The owner or operator of an existing

affected source shall comply with the emission limitations in

Sec. 63.342 as follows:

(i) No later than 1 year after January 25, 1995, if the affected

source is a decorative chromium electroplating tank; and

(ii) No later than 2 years after January 25, 1995, if the affected

source is a hard chromium electroplating tank or a chromium anodizing

tank.

(2) The owner or operator of a new or reconstructed affected source

that has an initial startup after January 25, 1995, shall comply

immediately upon startup of the source. The owner or operator of a new

or reconstructed affected source that has an initial startup after

December 16, 1993 but before January 25, 1995, shall follow the

compliance schedule of Sec. 63.6(b) (3) and (4).

Table 1 to Sec. 63.342.--Summary of Work Practice Standards

----------------------------------------------------------------------------------------------------------------

Control technique Work practice standards Frequency

----------------------------------------------------------------------------------------------------------------

Composite mesh-pad (CMP) 1. Visually inspect device to ensure there is proper 1. 1/quarter.

system. drainage, no chronic acid buildup on the pads, and no

evidence of chemical attack on the structural

integrity of the device.

2. Visually inspect back portion of the mesh pad 2. 1/quarter.

closest to the fan to ensure there is no breakthrough

of chromic acid mist.

3. Visually inspect ductwork from tank to the control 3. 1/quarter.

device to ensure there are no leaks.

4. Perform washdown of the composite mesh-pads in 4. Per manufacturer.

accordance with manufacturers recommendations.

Packed-bed scrubber (PSB) 1. Visually inspect device to ensure there is proper 1. 1/quarter.

drainage, no chromic acid buildup on the packed beds,

and no evidence of chemical attack on the structural

integrity of the device.

2. Visually inspect back portion of the chevron blade 2. 1/quarter.

mist eliminator to ensure that it is dry and there is

no breakthrough of chromic acid mist.

3. Same as number 3 above.............................. 3. 1/quarter.

[[Page 4967]]

4. Add fresh makeup water to the top of the packed bed 4. Whenever makeup is added.

a,b.

PBS/CMP system........... 1. Same as for CMP system.............................. 1. 1/quarter.

2. Same as for CMP system.............................. 2. 1/quarter.

3. Same as for CMP system.............................. 3. 1/quarter.

4. Same as for CMP system.............................. 4. Per manufacturer.

Fiber-bed mist 1. Visually inspect fiber-bed unit and prefiltering 1. 1/quarter.

eliminatorc. device to ensure there is proper drainage, no chromic

acid buildup in the units, and no evidence of chemical

attack on the structural integrity of the devices.

2. Visually inspect ductwork from tank or tanks to the 2. 1/quarter.

control device to ensure there are no leaks.

3. Perform washdown of fiber elements in accordance 3. Per manufacturer.

with manufacturers recommendations.

Air pollution control To be proposed by the source for approval by the To be proposed by the source

device (APCD) not listed Administrator. for approval by the

in rule. Administrator.

----------------------------------------------------------------------------------------------------------------

Monitoring Equipment

----------------------------------------------------------------------------------------------------------------

Pitot tube............... Backflush with water, or remove from the duct and rinse 1/quarter.

with fresh water. Replace in the duct and rotate 180

degrees to ensure that the same zero reading is

obtained. Check pitot tube ends for damage. Replace

pitot tube if cracked or fatigued.

Stalagmometer............ Follow manufacturers recommendations................... ............................

----------------------------------------------------------------------------------------------------------------

aIf greater than 50 percent of the scrubber water is drained (e.g., for maintenance purposes), makeup water may

be added to the scrubber basin.

bFor horizontal-flow scrubbers, top is defined as the section of the unit directly above the packing media such

that the makeup water would flow perpendicular to the air flow through the packing. For vertical-flow units,

the top is defined as the area downstream of the packing material such that the makeup water would flow

countercurrent to the air flow through the unit.

cWork practice standards for the control device installed upstream of the fiber-bed mist eliminator to prevent

plugging do not apply as long as the work practice standards for the fiber-bed unit are followed.

(3) The owner or operator of an existing area source that increases

actual or potential emissions of hazardous air pollutants such that the

area source becomes a major source must comply with the provisions for

existing major sources, including the reporting provisions of

Sec. 63.347(g), immediately upon becoming a major source.

(4) The owner or operator of a new area source (i.e., an area

source for which construction or reconstruction was commenced after

December 16, 1993) that increases actual or potential emissions of

hazardous air pollutants such that the area source becomes a major

source must comply with the provisions for new major sources,

immediately upon becoming a major source.

(5) An owner or operator of an existing hard chromium

electroplating tank or tanks located at a small, hard chromium

electroplating facility that increases its maximum cumulative potential

rectifier capacity, or its actual cumulative rectifier capacity, such

that the facility becomes a large, hard chromium electroplating

facility must comply with the requirements of Sec. 63.342(c)(1)(i) for

all hard chromium electroplating tanks at the facility no later than 1

year after the month in which monthly records required by

Secs. 63.342(c)(2) and 63.346(b)(12) show that the large designation is

met.

(6) Request for an extension of compliance. An owner or operator of

an affected source or sources that requests an extension of compliance

shall do so in accordance with this paragraph and the applicable

paragraphs of Sec. 63.6(i). When the owner or operator is requesting

the extension for more than one affected source located at the

facility, then only one request may be submitted for all affected

sources at the facility.

(i) The owner or operator of an existing affected source who is

unable to comply with a relevant standard under this subpart may

request that the Administrator (or a State, when the State has an

approved part 70 permit program and the source is required to obtain a

part 70 permit under that program, or a State, when the State has been

delegated the authority to implement and enforce the emission standard

for that source) grant an extension allowing the owner or operator up

to 1 additional year to comply with the standard for the affected

source. The owner or operator of an affected source who has requested

an extension of compliance under this paragraph and is otherwise

required to obtain a title V permit for the source shall apply for such

permit or apply to have the title V permit revised to incorporate the

conditions of the extension of compliance. The conditions of an

extension of compliance granted under this paragraph will be

incorporated into the owner or operator's title V permit for the

affected source(s) according to the provisions of 40 CFR part 70 or 40

CFR part 71, whichever is applicable.

(ii) Any request under this paragraph for an extension of

compliance with a relevant standard shall be submitted in writing to

the appropriate authority not later than 6 months before the affected

source's compliance date as specified in this section.

(7) An owner or operator of a decorative chromium electroplating

tank that uses a trivalent chromium bath that incorporates a wetting

agent, and that ceases using the trivalent chromium process, must

comply with the emission limitation now applicable to the tank within 1

year of switching bath operation.

(b) Methods to demonstrate initial compliance. (1) Except as

provided in paragraphs (b)(2) and (b)(3) of this section, an owner or

operator of an affected source subject to the requirements of this

subpart is required to conduct an initial performance test as required

under Sec. 63.7, using the [[Page 4968]] procedures and test methods

listed in Sec. 63.7 and Sec. 63.344.

(2) If the owner or operator of an affected source meets all of the

following criteria, an initial performance test is not required to be

conducted under this subpart:

(i) The affected source is a decorative chromium electroplating

tank or a chromium anodizing tank; and

(ii) A wetting agent is used in the plating or anodizing bath to

inhibit chromium emissions from the affected source; and

(iii) The owner or operator complies with the applicable surface

tension limit of Sec. 63.342(d)(2) as demonstrated through the

continuous compliance monitoring required by paragraph (c)(5)(ii) of

this section.

(3) If the affected source is a decorative chromium electroplating

tank using a trivalent chromium bath, and the owner or operator is

subject to the provisions of Sec. 63.342(e), an initial performance

test is not required to be conducted under this subpart.

(c) Monitoring to demonstrate continuous compliance. The owner or

operator of an affected source subject to the emission limitations of

this subpart shall conduct monitoring according to the type of air

pollution control technique that is used to comply with the emission

limitation. The monitoring required to demonstrate continuous

compliance with the emission limitations is identified in this section

for the air pollution control techniques expected to be used by the

owners or operators of affected sources.

(1) Composite mesh-pad systems. (i) During the initial performance

test, the owner or operator of an affected source, or a group of

affected sources under common control, complying with the emission

limitations in Sec. 63.342 through the use of a composite mesh-pad

system shall determine the outlet chromium concentration using the test

methods and procedures in Sec. 63.344(c), and shall establish as a

site-specific operating parameter the pressure drop across the system,

setting the value that corresponds to compliance with the applicable

emission limitation, using the procedures in Sec. 63.344(d)(5). An

owner or operator may conduct multiple performance tests to establish a

range of compliant pressure drop values, or may set as the compliant

value the average pressure drop measured over the three test runs of

one performance test and accept 1 inch of water column from

this value as the compliant range.

(ii) On and after the date on which the initial performance test is

required to be completed under Sec. 63.7, the owner or operator of an

affected source, or group of affected sources under common control,

shall monitor and record the pressure drop across the composite mesh-

pad system once each day that any affected source is operating. To be

in compliance with the standards, the composite mesh-pad system shall

be operated within 1 inch of water column of the pressure

drop value established during the initial performance test, or shall be

operated within the range of compliant values for pressure drop

established during multiple performance tests.

(2) Packed-bed scrubber systems. (i) During the initial performance

test, the owner or operator of an affected source, or group of affected

sources under common control, complying with the emission limitations

in Sec. 63.342 through the use of a packed-bed scrubber system shall

determine the outlet chromium concentration using the procedures in

Sec. 63.344(c), and shall establish as site-specific operating

parameters the pressure drop across the system and the velocity

pressure at the common inlet of the control device, setting the value

that corresponds to compliance with the applicable emission limitation

using the procedures in Sec. 63.344(d) (4) and (5). An owner or

operator may conduct multiple performance tests to establish a range of

compliant operating parameter values. Alternatively, the owner or

operator may set as the compliant value the average pressure drop and

inlet velocity pressure measured over the three test runs of one

performance test, and accept 1 inch of water column from

the pressure drop value and 10 percent from the velocity

pressure value as the compliant range.

(ii) On and after the date on which the initial performance test is

required to be completed under Sec. 63.7, the owner or operator of an

affected source, or group of affected sources under common control,

shall monitor and record the velocity pressure at the inlet to the

packed-bed scrubber and the pressure drop across the scrubber system

once each day that any affected source is operating. To be in

compliance with the standards, the scrubber system shall be operated

within 10 percent of the velocity pressure value

established during the initial performance test, and within

1 inch of water column of the pressure drop value

established during the initial performance test, or within the range of

compliant operating parameter values established during multiple

performance tests.

(3) Packed-bed scrubber/composite mesh-pad system. The owner or

operator of an affected source, or group of affected sources under

common control, that uses a packed-bed scrubber in conjunction with a

composite mesh-pad system to meet the emission limitations of

Sec. 63.342 shall comply with the monitoring requirements for composite

mesh-pad systems as identified in paragraph (c)(1) of this section.

(4) Fiber-bed mist eliminator. (i) During the initial performance

test, the owner or operator of an affected source, or group of affected

sources under common control, complying with the emission limitations

in Sec. 63.342 through the use of a fiber-bed mist eliminator shall

determine the outlet chromium concentration using the procedures in

Sec. 63.344(c), and shall establish as a site-specific operating

parameter the pressure drop across the fiber-bed mist eliminator and

the pressure drop across the control device installed upstream of the

fiber bed to prevent plugging, setting the value that corresponds to

compliance with the applicable emission limitation using the procedures

in Sec. 63.344(d)(5). An owner or operator may conduct multiple

performance tests to establish a range of compliant pressure drop

values, or may set as the compliant value the average pressure drop

measured over the three test runs of one performance test and accept

1 inch of water column from this value as the compliant

range.

(ii) On and after the date on which the initial performance test is

required to be completed under Sec. 63.7, the owner or operator of an

affected source, or group of affected sources under common control,

shall monitor and record the pressure drop across the fiber-bed mist

eliminator, and the control device installed upstream of the fiber bed

to prevent plugging, once each day that any affected source is

operating. To be in compliance with the standards, the fiber-bed mist

eliminator and the upstream control device shall be operated within

1 inch of water column of the pressure drop value

established during the initial performance test, or shall be operated

within the range of compliant values for pressure drop established

during multiple performance tests.

(5) Wetting agent-type or combination wetting agent-type/foam

blanket fume suppressants. (i) During the initial performance test, the

owner or operator of an affected source complying with the emission

limitations in Sec. 63.342 through the use of a wetting agent in the

electroplating or anodizing bath shall determine the outlet chromium

concentration using the procedures in Sec. 63.344(c). The owner or

operator shall establish as the site-specific operating parameter the

surface tension of the bath using Method 306B, appendix A of

[[Page 4969]] this part, setting the maximum value that corresponds to

compliance with the applicable emission limitation. In lieu of

establishing the maximum surface tension during the performance test,

the owner or operator may accept 45 dynes/cm as the maximum surface

tension value that corresponds to compliance with the applicable

emission limitation. However, the owner or operator is exempt from

conducting a performance test only if the criteria of paragraph (b)(2)

of this section are met.

(ii) On and after the date on which the initial performance test is

required to be completed under Sec. 63.7, the owner or operator of an

affected source shall monitor the surface tension of the electroplating

or anodizing bath. Operation of the affected source at a surface

tension greater than the value established during the performance test,

or greater than 45 dynes/cm if the owner or operator is using this

value in accordance with paragraph (c)(5)(i) of this section, shall

constitute noncompliance with the standards. The surface tension shall

be monitored according to the following schedule:

(A) The surface tension shall be measured once every 4 hours during

operation of the tank with a stalagmometer or a tensiometer as

specified in Method 306B, appendix A of this part.

(B) The time between monitoring can be increased if there have been

no exceedances. The surface tension shall be measured once every 4

hours of tank operation for the first 40 hours of tank operation after

the compliance date. Once there are no exceedances during 40 hours of

tank operation, surface tension measurement may be conducted once every

8 hours of tank operation. Once there are no exceedances during 40

hours of tank operation, surface tension measurement may be conducted

once every 40 hours of tank operation on an ongoing basis, until an

exceedance occurs. The minimum frequency of monitoring allowed by this

subpart is once every 40 hours of tank operation.

(C) Once an exceedance occurs as indicated through surface tension

monitoring, the original monitoring schedule of once every 4 hours must

be resumed. A subsequent decrease in frequency shall follow the

schedule laid out in paragraph (c)(5)(ii)(B) of this section. For

example, if an owner or operator had been monitoring an affected source

once every 40 hours and an exceedance occurs, subsequent monitoring

would take place once every 4 hours of tank operation. Once an

exceedance does not occur for 40 hours of tank operation, monitoring

can occur once every 8 hours of tank operation. Once an exceedance does

not occur for 40 hours of tank operation on this schedule, monitoring

can occur once every 40 hours of tank operation.

(iii) Once a bath solution is drained from the affected tank and a

new solution added, the original monitoring schedule of once every 4

hours must be resumed, with a decrease in monitoring frequency allowed

following the procedures of paragraphs (c)(5)(ii) (B) and (C) of this

section.

(6) Foam blanket-type fume suppressants. (i) During the initial

performance test, the owner or operator of an affected source complying

with the emission limitations in Sec. 63.342 through the use of a foam

blanket in the electroplating or anodizing bath shall determine the

outlet chromium concentration using the procedures in Sec. 63.344(c),

and shall establish as the site-specific operating parameter the

thickness of the foam blanket, setting the minimum thickness that

corresponds to compliance with the applicable emission limitation. In

lieu of establishing the minimum foam blanket thickness during the

performance test, the owner or operator may accept 2.54 centimeters (1

inch) as the minimum foam blanket thickness that corresponds to

compliance with the applicable emission limitation. All foam blanket

measurements must be taken in close proximity to the workpiece or

cathode area in the plating tank(s).

(ii) On and after the date on which the initial performance test is

required to be completed under Sec. 63.7, the owner or operator of an

affected source shall monitor the foam blanket thickness of the

electroplating or anodizing bath. Operation of the affected source at a

foam blanket thickness less than the value established during the

performance test, or less than 2.54 cm (1 inch) if the owner or

operator is using this value in accordance with paragraph (c)(6)(i) of

this section, shall constitute noncompliance with the standards. The

foam blanket thickness shall be measured according to the following

schedule:

(A) The foam blanket thickness shall be measured once every 1 hour

of tank operation.

(B) The time between monitoring can be increased if there have been

no exceedances. The foam blanket thickness shall be measured once every

hour of tank operation for the first 40 hours of tank operation after

the compliance date. Once there are no exceedances for 40 hours of tank

operation, foam blanket thickness measurement may be conducted once

every 4 hours of tank operation. Once there are no exceedances during

40 hours of tank operation, foam blanket thickness measurement may be

conducted once every 8 hours of tank operation on an ongoing basis,

until an exceedance occurs. The minimum frequency of monitoring allowed

by this subpart

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National Emission Standards for Chromium Emissions From Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks · 60 FR 4948 | Frix